Daily Archives: July 2, 2021

The long double file of scarlet-robed doctors which processed, at this years brilliant Commemoration at Oxford, from Wadham, the vice-chancellors College, to the Sheldonian Theatre was, from the feminists point of view, less interesting from its inclusion of the prime minister, the chancellor of the exchequer, Lord Jellicoe, and the archbishop of Canterbury, than from the unique event that it contained a woman.

Miss Annie Cannon, the eminent astronomer from Harvard Observatory, on whom, on June 10, Oxford conferred an honorary Doctor of Science degree, walked in procession with her host, Professor Turner, Oxfords Savilian professor of astronomy, and the crowd which had come out to look at the prime minister found its sensation instead in this startling precedent of a woman in a procession consecrated to academic masculinity and distinguished male service.

In honour of her visit to England, Professor Turner gave a lecture at Sommerville on Miss Cannons invaluable contribution to astronomy, and linked it to the wonderful tradition created by Mary Somerville after whom Oxfords famous womens college is named and Caroline Herschel, whose gold medal is now in possession of Girton.

Dr Annie Cannon is to-day carrying on the work of her two famous forerunners. With the help of the spectrum she has classified 25,000 stars in the northern and southern hemisphere according to their heat as well as their substance, distance and velocity. It remained for Professor Eddington to order this accumulated data by his theory that nebula evolve from a low through a high temperature back to a low one again. Thus the aim of William and Caroline Herschel was achieved, and the life of the nebula traced as the life of a planet.

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Oxford recognises Annie Cannons invaluable contribution to astronomy archive, 1925 - The Guardian

Authors note: This piece references harassment and other potentially uncomfortable experiences.

I would have been lost if not for this one, singular professor who made it her lifes work to get me to stay in astronomy. Thats Fletcher Waller, a masters student at the University of Victoria who uses spectroscopy to study populations of metal-poor stars in the Local Group, explaining why hes still a scientist. Unlike more privileged individuals, his journey through astronomy has been shaped not just by his chosen specialty, but also by a fundamental part of his identity. Waller is transgender, and in a field that remains dominated by straight, cisgender white men, being queer often means constantly having to worry about harassment and abuse. While his supervisor went to extraordinary efforts to ensure that he felt supported, having a close ally is the exception, not the rule. As Waller puts it, The department is so cis-het that its impossible to know who is even remotely safe to go to.

I interviewed 14 current and former astronomers who identify as part of the LGBTQ+ community. Some, like Dr. Kaitlin Rasmussen, a spectroscopist at the University of Michigan, have survived bigoted environments through sheer determination. Others, faced with intense discrimination, have been forced out of astronomy entirely. Our conversations covered queerphobia in the field, resources for both LGBTQ+ astronomers and allies, and what individuals and institutions can do to provide safer and more inclusive environments. At a time when societal acceptance of the queer community is growing but significant structural barriers to equality remain, actions or field takes today are crucial to the survival of LGBTQ+ astronomers. Today, in the first half of this two-part Astrobite, Ill introduce you to some of the folks I talked to, the challenges they face, and the ways astronomy has failed them so far.

Dr. Claudia Antolini is a science communicator based in the United Kingdom. Antolini identifies as asexual, and throughout her years in academia, she experienced harassment from those who either didnt understand her sexuality or simply didnt care. She described having to run away and hide from men who continually made unwanted advances, summing up her experiences by saying, I could tell you things that would make your skin crawl.

Antolinis encounters are far from atypical both of women and of queer people in astronomy. I spoke with a former graduate student who asked a professor for a letter of recommendation for his PhD application while finishing his masters degree. The professor told him no ones gonna hire [you] because [youre] trans. While the student eventually found a professor to do his PhD work with, this professor was disdainful after finding out about his transition; subsequently, he lost his funding and, subsequently, their apartment. He left astronomy, and has found it extremely difficult to reenter the field.

Some of the more insidious barriers queer astronomers face are those others view as trivial. Avery Kiihne, an undergraduate at Rutgers studying star formation in dwarf galaxies, encountered difficulties when changing their name. Administrative mishandling led to Kiihne having to use their deadname on certain forms seen by colleagues and supervisors, and they received an aggressive response when they tried to correct the matter. A problem that should have been solved in a day turned into a drawn-out, emotional ordeal.

Departments arent the only places where queer astronomers face the potential for discrimination, harassment, or assault. Conference organizers should be cognizant of the potential for meetings to be hostile environments. Recent legislation in certain states and jurisdictions has made it harder for nonbinary and transgender individuals to access the bathroom of their gender identity, which groups should take into account. International conferences should also strive to avoid regions where queerphobia is rampant. Winter Parts, a nonbinary PhD student at Penn State University studying exoplanets, brings up the example of a friend of theirs attending a conference in Dubai, where LGBTQ+ rights are nearly nonexistent. Parts was concerned about whether they could safely attend the conference.

Finally, there are the everyday microaggressions that slowly contribute to a climate of animosity. Waller faced hostile looks when he used gendered restrooms because his department lacked gender-neutral restrooms. One student I spoke to describes an instance they were told of where a professor made no effort to understand the purpose of properly using personal pronouns an uncomfortable situation because of the potential for misgendering.

When attempting to improve inclusivity, many astronomy departments treat LGBTQ+ astronomers as a singular, inseparable group an assumption that is at best naive, and at worst actively harmful. As Antolini puts it, The queer community is extremely varied, and all the different layers of the our full identities will take us down a very different path. For example, being a person of color and gay is an extremely different experience than being white and gay. Nicole Man, now a data scientist at the Pacific Northwest National Laboratory, notes that overwhelmingly white queer spaces alienated her, saying, I think my experience as a queer scientist and astrophysicist has also been tied with my identity as a woman of color. I think a lot of the times when I did try to be a part of the communities that were queer, I did feel like I had to fracture other parts of my identity in order to have some common ground with them. At a time when astronomy departments are grappling with systemic racism in the field, ignoring intersectionality when working on inclusivity initiatives is a recipe for disaster.

A similarly problematic assumption is that all queer people are essentially the same; in reality, LGBTQ+ folks have varying needs. For example, transgender, intersex and nonbinary individuals urgently need gender-neutral restrooms an issue most astronomy departments have utterly failed to address. Antolini points out that unlike other sexual orientations, asexuality is not a protected characteristic in the United Kingdom, meaning asexual folks may need additional departmental support for addressing academic harassment. Its possible that a lack of representation of many queer groups throughout history and in modern media has contributed to this one-dimensional view of LGBTQ+ people. While gay astronomers and physicists can look up to the likes of Frank Kameny and Sally Ride, Antolini puts her own experience as an asexual scientist bluntly: We have no Alan Turing.

Finally, departments often fail to understand the importance of particular support systems in the queer community. Charlotte Olsen, a graduate student at Rutgers University working on distant galaxies, emphasizes the importance of a queer persons chosen family, the individuals who support, comfort and care for them, particular in the absence of a normal family structure: I think that there are times when the academy doesnt recognize the importance of chosen family, because its not something thats really super well understood. So, for example, participating in pride events or doing stuff at the local LGBT Center, people who participate in the balls or anything like that a lot of times people who are outside of the gay community see these as hobbies, or special interests. . . . For some of us our chosen family is the only family that we have.

Being queer in science entails an invisibility that other underrepresented minorities dont face. The fact that you cant tell whether someone is gay or trans or asexual just by looking at them can be both a blessing and a curse, a shield for individuals against potential harassment and a shield for institutions pretending or assuming that this harassment doesnt exist at all. Unfortunately, some of the hostility incumbent in the current climate in astronomy compounds this invisibility by forcing queer astronomers to hide part of who they are. One PhD student I talked with says that while she is still not out, seeing other queer people thriving in the field brings her happiness and hope, and I hope that we can work towards a fully inclusive community, where more LGBTQ+ astronomers are able to enjoy this freedom. Tomorrow, Ill look at what measures the field can take to better support queer astronomers, discuss some of the resources and support systems already in place, and take a peek down the path we can take to a more welcoming astronomy community.

Astrobite edited by Lili Alderson and Luna Zagorac.

Featured image credit: Laurie Raye

About Graham DoskochI'm a first-year graduate student at West Virginia University, pursuing a PhD in radio astronomy. My focus is on neutron stars and pulsar timing, a method of detecting gravitational waves by monitoring arrays of pulsars over the course of many years. I'm an associate member of NANOGrav, and I'm starting to help with their ongoing timing efforts.I love running, hiking, reading, and just enjoying nature.

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Queer Astronomy, Part 1: Acknowledging the problem | astrobites - Astrobites

Thank heavens for the Royal Observatorys Astronomy Photographer of the Year awards. After most of us spent the better part of a year shut inside, the worlds brightest and best astrophotography stars are here to remind us of the spectacle of whats out there.

The shortlisted images include a stunning shot of comet Neowise screaming past Stonehenge, a magical glimpse of the Northern Lights as seen from a frozen river in Iceland, and an awe-inspiring photo of a dying star named the Dolphin Head Nebula.

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its thirteenth year. This year the competition received over 4,500 entries from enthusiastic amateurs and professional photographers, taken from 75 countries across the globe.

Winners will be announced on the 16th September, and then displayed at the National Maritime Museum from Saturday 18 September.

Heres our favourite images from this years batch. If these inspire you, why not try your hand at a bit of astrophotography with the help of our guide to astronomy for beginners.

Stefan Liebermann

A mesmerising panorama of the Milky Way over the lavender fields in Valensole, France. Parallel rows of flowers set against a heavenly dome make for a stunning image, even though the light pollution the golden orange hue is clearly visible over the whole area. The foreground was captured in the blue hour (twilight) with the camera set to a high ISO value since the wind means the lavender never stands still.

Matt Naylor

Here the photographers managed to pull off a rare feat: capturing the Moon and the famous Lovell Telescope in one image. Finding a spot with a clear view, far enough away from the subject, and the Moon being in the sky at the correct time of day was all part of the puzzle. By the time the Moon appeared, the photographer had to drop down the focal length to 286mm to compose this image.

Yovin Yahathugoda

This is an image of the Dolphin Head Nebula, also designated as Sharpless 308, located at the centre of the constellation Canis Major. The star at the centre of this image is dying. The stars gravity became too weak to hold onto its outer layers, and so they were blown away by stellar winds generated by nuclear reactions deep within. The stars surface material is blown out into space, creating this nebula, a giant cloud of gas and dust. Eventually, the star will go supernova and die. The photographer struggled to capture this nebula for over a month due to poor conditions and was thrilled to get just 1.5 hours of total exposure time spread over 3 nights. The raw data was acquired using the Telescope Live remote telescope in Chile.

Andrew McCarthy

This image shows how the magnetic field of the Sun pulls up portions of the chromosphere following a large solar flare, with the magnetic field lines on crystal clear display along the limb in hydrogen-alpha light. This also happened while a particularly large active region was along the face of the solar disc. This was captured in black and white and processed partially inverted to highlight the contrast on the surface as well as the atmospheric features on the limb, presented in false colour for the aesthetic. This was one of the most interesting features on the Sun in all of 2020 and represents the first major activity since the start of the new solar cycle.

Yang Sutie

As the photographer was driving on the mountain road at Ranwu, Tibet, China, he saw a mound on the right side of the road. The mountains and the Milky Way were lined-up in front of the photographer, so he stopped and climbed up the side of the road, set the camera to shoot automatically, and then drove back and forth in this curve. Then he climbed up the hillside and integrated himself into the picture.

Jean-Claude Canonne, Didier Chaplain, Georges Chassaigne, Philippe Bernhard, Laurent Bourgon and Nicolas Outters

This image, captured by the Cielaustral team, is a large mosaic covering a wide portion of the sky and allowing us to admire incredible details in the gaseous structures. The team acquired both narrowband images in hydrogen-alpha, doubly ionised oxygen and singly ionised sulphur spectral lines as well as natural colour images using red, green and blue filters. The total exposure time of all the frames needed to compose these majestic images is 253 hours.

Vitaliy Novikov

Capturing the polar lights in Murmansk wasnt an easy feat for the photographer because of the bright lights in the city. To photograph the Aurora Borealis in Murmansk, Russia, you must wait for a very strong solar flare. The photographer was able to capture the Aurora over the Kola Bay after several attempts and many hours of waiting and wanted to showcase this optical phenomenon in an urban landscape.

Pter Feltti

The Veil Nebula complex is the remnant of a giant supernova explosion. This image shows only a part of the complex as the entire nebula is around 6 times the diameter of the full Moon. Objects of this type can be photographed very effectively with narrowband filters. The photographer processed a bicolour photo from monochrome images of hydrogen-alpha and oxygen emissions.

Anthony Sullivan

The Milky Way is rising over Durdle Door, Dorset, United Kingdom. This is a perfect spot for astrophotography as the landscape is so fascinating and aligns with the Milky Way core during a few months of the year. Saturn and Jupiter can also be seen to the left of the frame, just above the horizon. To achieve less noise in the image, the photographer used a star tracking mount to lengthen the cameras shutter speed. However this also creates motion blur in the foreground, so two images were blended together to produce the final result.

Steven Mohr

The Dark Molecular Cloud found in the constellation Corona Australis, lies some 554 light-years away from Earth, and this field of view is spanning approximately the size of a full Moon. To the left of the image, far in the distance, is the globular cluster NGC6723 which is some 28,400 light-years away. NGC6723 resides just within the constellation border of Sagittarius.

Markus van Hauten

The photographer always wanted to capture a picture like this. During a visit to Breidamerkurjkull, Iceland, in January 2020, he decided to do a double exposure one from the cave and one of the Aurora Borealis and stacked them together. The weather conditions that day were ideal, and the final result came out perfectly.

Masoud Ghadiri

This image showcases the splendour of Mount Damavand. Located north-east of the city of Tehran it is approximately 5,670 metres high and according to the photographer it is one of the most beautiful natural wonders of Iran. The Milky Way is shining on the left of the sky, and you can see Tehrans light pollution on the right. The photo was taken from the mountain at Nandal village beside a small lake and the photographer had to hike for about seven hours and ascend more than 1,000 metres to get there. The photo contains ten stacked images, five for the sky and five for the foreground.

Steven Mohr

The Flame Nebula, designated as NGC 2024 and Sh2-277, is an emission nebula in the constellation Orion, lying some 900 to 1,500 light-years away from Earth. The bright star Alnitak (just outside the field of view at the top of this image), the easternmost star in the Belt of Orion, shines energetic ultraviolet light into the Flame and this knocks electrons away from the great clouds of hydrogen gas that reside there. Much of the glow results when the electrons and ionised hydrogen recombine. Additional dark gas and dust lies in front of the bright part of the nebula, and this is what causes the dark network that appears in the centre of the glowing gas.

If you are enjoying this gallery, why not check out some of our other sets:

Wang Zheng

In the Tengger Desert, located in Minqin County, Wuwei City, China, there is a mysterious group of artificial sculptures. The metal columns that point to the sky in this picture are called raindrops. By day, it falls like a raindrop in the desert, but the photographer prefers it at night under the Milky Way. After the Moon sets, the metal sculpture reflects the light of the Milky Way, making the sculptures outline very clear. Extremely bright starlight in the desert is reflected off the metal surface like a column of light from a vast universe of stars hitting the ground.

Ivan Vucetic

The photograph shows a captivating star trail over Dugi Otok in Croatia and the extraordinary relationship between our Planet and the Universe in a way that the human eye cannot perceive it. The photographer intended to capture the reflection of the stars on the water together with the sky, however during the long exposure time that was necessary for star trails the wind increased and seeing conditions were not favourable enough for a clear reflection of the stars. The photographer had to use the stars from the sky in post-processing to achieve the final result.

Damian Peach

In this image, taken in La Palma, Mucia, Spain, Saturn is shown near its best for 2020, displaying a wealth of details across the globe and ring system. The famous polar hexagon can be seen around the pole at bottom, while many other belts and zones are seen across the planet. The Cassini and Encke divisions dominate the view of the rings.

Larryn Rae

This is a 250 panorama of the Aurora Borealis in Iceland. The photographer came across this estuary that reflected the sky perfectly on a well below freezing winters night, and captured the panorama first, and then took a shot of himself out on the ice. For the photographer this is one of the most amazing aurora images that he has ever captured, and it sums up an awe-inspiring trip to Iceland in wintertime that also emphasised the feeling of being just a tiny part of the planets existence in the face of a very powerful natural environment.

Pter Feltti

Photographing galaxies has excited the photographers imagination for a long time, as has putting well-known subjects into unusual and unexpected compositions away from traditional depictions. A good way to do this is to show a galaxy in such a way that it completely fills the field of view and that is exactly what the photographer accomplished here with the Andromeda Galaxy.

Benjamin Barakat

This magnificent chteau in Chambord, Centre-Val de Loire, France, was an amazing location chosen by the photographers best friend and mentor Ralf Rohner, but it proved to be a challenging one as the castle had intervals of illumination with a minutes pause every 15 minutes. During the pauses, the photographer shot away trying to get as many images as possible and while processing it he had to try to mimic the reflection due to the time delay caused by the castle lights.

Jiajun Hua

Shanghai is one of the most economically developed cities in China. The photo is taken 16 kilometres away from Lujiazui financial district. Every year there are only a few weeks when photographers can capture the scene of the Sun rising over the Central Business District. The photographer waited for a few days and finally witnessed the Sun rising from the most prosperous area of Shanghai on a heavily polluted morning. The photo is composed of four different exposures from the same perspective, recording the process of the Sun rising.

James Rushforth

The image depicts the Comet NEOWISE passing over Stonehenge in the United Kingdom. The orange glow is light pollution from the nearby villages of Durrington and Larkhill, and a passing lorry very kindly painted the rocks with light. For the photographer, the thought that this historic site did not exist when the comet NEOWISE last passed the Earth is quite fascinating. The comet is due to return in approximately 6,800 years. The photograph is a single exposure taken early on the morning of 20 July 2020.

Daning Kai

This image shows star trails over the Lujiazui city in Pudong District, and you can even distinguish the Belt of Orion. Lujiazui is the most prosperous place in Shanghai, China and the light pollution is very heavy but if the weather is clear, you can see the stars. The photographer captured this photo on a very clear autumn night. The beautiful starry sky is above us, and even if you live in a city, and you can still look up at it.

Antoni Cladera Barcel

Menorca was declared a Biosphere Reserve by UNESCO in 1993 and credited as a Starlight Reserve in 2019. The photographer captured this image at this natural stone bridge shaped by water erosion at Pont den Gil, Ciutadella, Spain. A watchman stands vigilant under the stars as the Milky Way is vertical above the natural arch. To add a soft and warm tone to the arch, the photographer used the light pollution from Mallorca, the neighbouring island. The photographer wanted to humanise the landscape and incorporate the human element in the composition to prove that we are just natures guests.

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Wonders of the Universe: 23 mind-blowing photos from the Astronomy Photographer of the Year 2021 shortlist - BBC Focus Magazine

The Tumult of the Sun Hassan Hatami

From a turbulent image of our star and an odd-looking Martian sunset to the mesmerizing Dolphin Head Nebula and a close-up of the International Space Station set against the Moon, the Royal Observatorys annualAstronomy Photographer of the Year competition has once again produced some astonishing images of our Solar System and of the deep sky.

Run by the Royal Observatory Greenwich in London in association withBBC Sky at Night Magazine and now in its thirteenth year, the competition this year received over 4,500 entries from around the world.

Here are eight of the Solar System and deep sky entries from Iran, Sri Lanka, China and even from the Martian surface, some of which will triumph and feature in the final 11 when the results are announced in September 2021.

Above: Using a specially selected image from NASAs Solar Dynamics Observatory collection, photographer Hassan Hatami from Iran used a combination of three wavelengths to create this image of the turbulent Sun.

The original images were taken by the SDO in January 2015 when our Sun was close to solar maximum.

Dolphin Head Nebula Yovin Yahathugoda

Above: interstellar winds create a perfect cosmic bubble in this bi-colour image of the Dolphin Head Nebula in the constellation Canis Major, the Big Dog. At the center of the image is a rare Wolf-Rayet star.

It took the photographer 1.5 hours exposure time over three nights to capture this image using a remote telescope in Chile.

Saturn at its Best Damian Peach

Above: ace planetary astrophotographer Damian Peach here shows-off an image of the ringed planet taken from La Palma, Murcia, Spain in July 2020.

Its polar hexagon can be seen around the pole at bottom, while many other belts and zones can be seen across the planet.

Martian Sunset John White

Above: When NASAs Mars Curiosity Rover captures images it dumps them on a server thats publicly available. Photographer John White searched over 390,000 images in the Mars Curiosity raw archive and found these four that show a sunset on the Red Planet.

Why is it blue? Unlike on Earth, blue light better penetrates the fine dust in the Martian atmosphere. The images were taken in April 2015.

A Daytime Transit Andrew McCarthy

Above: the International Space Station (ISS) transiting a slim waning crescent Moon during daylight. Shot in Elk Grove, California in October 2020, this ISS transit of the Moon was captured using two cameras and two telescopes.

The Rose Josep Drudis

Above: the Ring Nebula (M57) is the glowing remains of a Sun-like star and a very famous planetary nebula previously photographed by the Hubble Space Telescope, but its rarely looked like this before. Taken with a professional Planewave CDK24 telescope in the near infra-red, you can see its faint halo as a collection of petals.

This image was taken with hydrogen (red) and oxygen (green and blue) filters, but also adding nitrogen (deep red). Taken from Mayhill, New Mexico, USA, during April, May and June 2020.

Pleiades Sisters Jashanpreet Singh Dingra

Above: Heres a gorgeous image taken in December 2020 from Patiala, Punjab, India by 14-year old Jashanpreet Singh Dingra. The Pleiadesalso known as the Seven Sisters and M45is an open star cluster containing middle-aged, hot B-type stars in constellation of Taurus, the Bull. The closest open cluster to the Solar System, the Pleiades is easy to see naked-eye.

Here the photographer has used a Takahashi FSQ-85ED telescope to reveal its nebulositythe hot gas between the stars and illuminated by themover the course of three hours of exposures.

NGC 3981 Bernard Miller

Above: The windswept NGC 3981 is a spiral galaxy about 65 million light years away in the constellation of Crater. Taken using a remote telescope in Chile in February 2021 over 34 hours.

Wishing you wide eyes and clear skies.

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In Photos: Angry Sun, A Blue Martian Sunset And Weird Dolphin Head Star In Astronomy Photographer Of The Year Entries - Forbes

A clash among members of a famous galaxy quintet reveals an assortment of stars across a wide color range, from young, blue stars to aging, red stars. Ancient Greek astronomers paved the way for our modern understanding of the heavens. Credit: NASAandESA Public Domain

Business moguls Sir Richard Branson and Jeff Bezos should be thanking ancient Greek astronomers for being able to realize their travel off the face of the earth and into space this month. Virgin Galactics Branson hopes to beat Amazon CEO Bezos to travel to space, announcing plans to be Astronaut 001 on the firms July 11 test flight.

As civilized societies were just learning to use the wheel on earth, the ancient Greeks were aiming at the sky and the stars, contemplating outer space and how to measure it.

Even the science of the study of the sky and the stars, astronomy, finds its root in the ancient Greek wordAstronomia.

It was under Greek skies that ancient astronomers began to develop theories about the planets overhead, theories that are now proven. Christopher Columbus may or may not have set out to prove that the earth was spherical, but it was the ancient Greek astronomer Aristarchus who initiated the theory that the universe is heliocentric and that the planets are round.

The Babylonians of Mesopotamia first looked to the skies and postulated that the stars, the moon and the sun as gods that ruled over men. However, it was the ancient Greeks who analyzed those theories of deities and turned them into mathematical equations and calculations.

If you really want to travel to the stars, there is an easier way than heading to Cape Canaveral, where NASA launches rockets from Florida into outer space, or getting an extraordinarily pricey ticket aboard the craft that Branson and Bezos will travel on this month.

If you can get to the Acropolis, just a few hundred meters away is the National Observatory, known in Greece as the Asteroskopeio. From the observatory, positioned directly across from the Acropolis on Lofos Nymphon in central Athens, you can get a birds eye view of Mars and the moon through the Doridis refractor telescope.

The National Observatory with a telescope that allows the public to view the stars directly across from the Acropolis. Credit: Dimboukas Creative CommonsAttribution 4.0 International

The National Observatory of Athens was founded in 1842, as the first research center of modern Greece. Its history is linked with the evolution of basic and applied research, the development of services provided to the Greek State and society at large, and the promotion of science.

And how amazing is it, that literally just steps away from where ancient Greek astronomers conducted their first experiments, contemporary Greek astronomers are working today and they can show you the planets in the night sky?

Metonas was a Greek mathematician, astronomer and engineer who lived in Athens in the 5th century BC. He is best known for the calculations he made for the Metonic cycle in 432 BC for the lunar calendar year of Attica.

Metonas calendar assumes that 19 solar years equals 235 lunar months, which equals 6,940 days. This system arose from calculations made by Metonas based on his own astronomical observations, which were confirmed by Aristarchus 152 years later.

According to the testimonies of ancient historians, Metonas installed the first Heliotropion, or Helioscope, in Pynx, a hellion Athens. The foundations of the Helioscope are still visible just behind the steps leading to Pnyx, the archaeological site perched on a small, rocky hill, just over 330 feet high in the center of Athens.

The site is in a large park, just below the National Observatory, to the west of the Acropolis. Metonas determined the dates of the equinoxes and the solstices based on the specific location of this helioscope.

From this position the sunrise during the summer solstice is seen from the top of Mt. Lycabettus, while six months later, during the winter solstice, the sun rises from the top of Mount Hymettus. The annual apparent movement of the sun on the horizon creates an arc of 60 degrees, the bisector of which is aligned with the rock of the Acropolis. The exact determination of the summer solstice was important to the ancient Athenians because the first moon, after the summer solstice, marked the beginning of the new year.

Metonas was one of many ancient Greek astronomers to formulate calculations while gazing at the skies above. Renowned mathematicians, many of these scholars, branched off in astronomy, cataloguing, calculating and observing. Whether they catalogued stars, contemplated shapes or tried to measure the physical space within and beyond the borders of earth, their work put contemporary man in the sky.

Today it is hard to believe in any other notion than spherical planets that revolve around the sun.

Pythagoras of Samos, who lived from 570 to 495 BC, was an ancient Greek astronomer and philosopher and the eponymous founder of Pythagoreanism. Pythagoras was credited with many mathematical and scientific discoveries in antiquity. Since at least the first century BC, Pythagoras has commonly been given credit for discovering the Pythagorean theorem in geometry, which states that in a right-angled triangle the square of the hypotenuse is equal (to the sum of) the squares of the two other sides.

It was said that he was the first man to call himself a philosopher, a lover of wisdom, in the Greek language, (philo/friend of sophia/wisdom). He was the first to divide the globe into five climatic zones.

In astronomy Pythagoras is credited with the belief that the earth is spherical and for identifying the morning and evening stars that we know today as the planet Venus. By the end of the fifth century BC, this fact was universally accepted among Greek intellectuals.

Philolaus, who lived from 470 to 385 BC, was a Greek Pythagorean and pre-Socratic philosopher. He was born in a Greek colony in Italy and migrated to Greece. Philolaus has been called one of three most prominent figures in the Pythagorean tradition and the most outstanding figure in the Pythagorean school.

Pythagoras developed a school of philosophy that was dominated by both mathematics and mysticism. Most of what is known today about the Pythagorean astronomical system is derived from Philolaus views. He may have been the first to write about Pythagorean doctrine.

Philolaus asserted that the earth was not the center of the universe, rebelling against the geo-centrism of the time. He is credited with the earliest known discussion of concepts in the development of heliocentrism, insisting the sun is the center of in the human universe.

Archimedes of Syracuse, who lived from 287 to 212 BC, was an ancient Greek astronomer, mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists of classical antiquity. The most widely known anecdote about Archimedes tells of how he invented a method for determining the volume of an object with an irregular shape.

Archimedes principle involved a metal bar, placed into a container of water, on a scale. It displaces as much water as its own volume, increasing the mass of the containers contents and weighing down the scale.

A votive crown for a temple had been made for the king of Syracuse, who had supplied the pure gold to be used. Archimedes was asked to determine whether some silver had been substituted by a dishonest goldsmith. Archimedes had to solve the problem without damaging the crown, so he could not melt it down into a regularly shaped body to calculate its density.

Archimedes noticed while taking a bath that the level of the water in the tub rose as he got in. He realized that this effect could be used to determine the volume of the crown. For practical purposes, water is incompressible so the submerged crown would displace an amount of water equal to its own volume.

By dividing the mass of the crown by the volume of water displaced, the density of the crown could be obtained. This density would be lower than that of gold if cheaper and less dense metals had been added. Archimedes then took to the streets naked, so excited by his discovery that he had forgotten to dress himself, crying Eureka, which in Greek sounds like evreeka, literally meaning, I have found it!

The test on the crown was conducted successfully, proving that silver had indeed been mixed in with the gold.

Archimedes also explored astronomical measurements of the earth, the sun and the moon, as well as Aristarchus heliocentric model of the universe. Despite a lack of trigonometry and a table of chords, Archimedes described the procedure and instrument used to make observations, a straight rod with pegs or grooves, applied correction factors to these measurements, and finally gave the result in the form of upper and lower bounds to account for observational error.

Ptolemy, quoting Hipparchus, also references Archimedes solstice observations in the Almagest. This would make Archimedes the first known ancient Greek astronomer to have recorded multiple solstice dates and times in successive years.

Ptolemy, 335-405 BC, used an astrolabe to record astronomical observations.

Today we know the exact time, the positions to the stars and planets, and our exact location, to the tenth of a degree but all these things were available to the ancient Greeks as well, in one device, thanks to the invention of the astrolabe.

The scientistPtolemy, who lived in Alexandria, was the brilliant mind behind this genius machine, which used sets of dials to determine altitude, latitude as long as the time was known the shifting positions of stars and planets, and to survey or triangulate your location on land.

Basically, the astrolabe was a handheld model of the universe. Its many functions also made it an elaborate inclinometer and an analog calculation device that was capable of working out several kinds of problems in astronomy.

The importance of the invention of the astrolabe comes not only from the early discoveries in astronomy, but also in determining latitude on land or on calm water, making it possible to navigate the seas in a limited way.

Aristarchus of Samos,who lived from 310 to c.230 BC, was an ancient Greek astronomer and mathematician who presented the first known heliocentric model that placed the sun at the center of the known universe, with the earth revolving around the sun once a year and rotating about its axis once a day. Aristarchus identified the central fire with the sun. He put the other planets in their correct order of distance around the sun.

Aristarchus suspected that the stars were just other bodies like the sun, albeit farther away from earth. His astronomical ideas were rejected in favor of the geocentric theories of Aristotle and Ptolemy.

Aristarchus estimated the sizes of the sun and moon as compared to earths size. He also estimated the distances from the earth to the sun and moon. He is considered one of the greatest astronomers of antiquity.

Aristarchus of Samos developed the first mathematical formula of astronomy to calculate planet size. Credit: Screenshot Youtube

Since Aristarchus suspected the stars were other suns that are very far away, there was no observable parallax that is, a movement of the stars relative to each other as the earth moves around the sun. Since stellar parallax is only detectable with telescopes, his accurate speculation was unprovable at the time.

It was not until the sixteenth century that a mathematical model of a heliocentric system was presented by the Renaissance mathematician, astronomer, and Catholic cleric, Nicolaus Copernicus, leading to the Copernican Revolution. In the following century, Johannes Kepler introduced elliptical orbits, and Galileo de Galilei presented supporting observations made using a telescope.

Eratosthenes of Cyrene, who lived from 276 BC to195 BC, was an ancient Greek astronomer who was also a multi-discipline scholar, or polymath. He was a mathematician, geographer, poet, astronomer and music theorist. He was a man of such learning that he also became the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography, and he introduced some of the terminology still used in that discipline today.

Eratosthenes is best known for being the first person known to calculate the circumference of the earth, which he did by using the extensive survey results he could access in his role at the Library of Alexandria. His calculation was remarkably accurate. He was also the first to calculate earths axial tilt, which also proved to have remarkable accuracy. He created the first global projection of the world, incorporating parallels and meridians based on the available geographic knowledge of his era.

Eratosthenes was the founder of scientific chronology. He endeavored to revise the dates of the main events of the semi-mythological Trojan War, dating the Sack of Troy to 1183 BC. In number theory, he introduced the sieve of Eratosthenes, an efficient method of identifying prime numbers.

The measurement of Earths circumference is the most famous among the results obtained by Eratosthenes, who estimated that the meridian has a length of 252,000 stadia, with an error on the real value of less than two percent. Eratosthenes described his arc measurement technique, in a book entitled On the measure of the Earth.

Hipparchus of Nicaea, 190120 BC, yet another ancient Greek astronomer, erected an early observatory on the island of Rhodes around 150 BC, and set about compiling a star catalogue with approximately 850 entries. He calculated the celestial coordinates for each star using the first known trigonometric table, and developed and improved several astronomical instruments, including the astrolabe.

Dedicated to Hipparchus contribution to the early study of the solar system, a crater on the surface of Mars, was named after him in 1973. A larger crater on the moon was also named after the ancient Greek astronomer.

The Antikythera Mechanism,often referred to as the worlds first computer, was discovered inside an ancient shipwreck by Greek sponge divers on May 17, 1901. After numerous studies, it was estimated to have been constructed between 150 BC and 100 BC.A later study places it at 205 BC,just seven years after the death of Archimedes.

The worlds oldest surviving mechanical calculator, it was used by ancient Greek astronomers. The device has now been somewhat deteriorated by the passage of time, but when intact it would have appeared as a box, housing dozens of finely machined bronze gear wheels.

When manually rotated by a handle, the gears spun dials on the exterior showing the phases of the moon, the timing of lunar eclipses, and the positions of the five planets then known (Mercury, Venus, Mars, Jupiter, and Saturn) at different times of the year. This even accounted for their retrograde motion an illusionary change in the movement of planets through the sky.

The moving parts of a a reproduction of the Antikythera Mechanism, an ancient analog computer. Credit: Freeth, T., Higgon, D., Dacanalis Creative CommonsAttribution 4.0 International

It may even have been the work of Archimedes himself, but there is no documentation of that, only speculation. Gearing technology with the sophistication of the Antikythera Mechanism was not seen again for one thousand years.

The ancient calculator also includes an astrological calendar, as the indicators seem to revolve around the zodiac, revealing the movements of both the moon and the planets.

A reproduction of the Antikythera Mechanism on display at the National Observatory in Athens. Credit: Moravec Creative CommonsAttribution-Share Alike 4.0 International

The National Observatory is the contemporary location for a journey to the stars. As noted above, the Asteroskopeio is within close proximity to the physical space used by ancient Greek astronomers who contributed so much to what we know of the universe today.

Ancient Greek astronomers such as Metonas, Pythagoras, Philolaus, Eratosthenes, Ptolemy, Aristarchus, Hipparchus, Archimedes developed the theories of calculation of the size, the time and the distance of planets within the human solar system. These contributions were the building blocks that made journeys off earth possible today.

Progress was marked by enlightened and renowned scientists in Greece who paved the way to knowledge with the creation of the Asteroskopeio in the 1800s. Thanks to the National Observatory, visitors to Athens can travel to the stars even if they are not Richard Branson or Jeff Bezos.

The tycoon Branson said, After more than 16 years of research, engineering, and testing, Virgin Galactic stands at the vanguard of a new commercial space industry, which is set to open space to humankind and change the world for good.

Lets hope he remembers to thank all those ancient Greek astronomers and not just the people who work for Virgin Galactic.

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Ancient Greek Astronomers -- And Modern Moguls -- Aim for the Stars - Greek Reporter

In the early 1900s, the universe seemed to be a much, much smaller place. Back then, astronomers believed the Milky Way galaxy was all there was. They didnt know there were billions of other galaxies; they didnt know how small we really are.

They didnt know this because they couldnt measure distances to far-flung stars. Why? There was a pretty simple problem in astronomy: A bright, faraway star looks almost the same as a dim star thats close by.

Its the same here on Earth. Imagine youre on the beach at night and see two lighthouse lights glowing in the distance, but one seems brighter than the other. If you knew both lighthouses used the same lightbulb, you could conclude that the dimmer light is farther away. But its also possible that the dimmer light just comes from a lower-wattage lightbulb, perhaps nearer to you.

Scientists needed a way to find out the intrinsic brightness of stars to figure out their wattage, so to speak. Thats when Henrietta Leavitt, a Massachusetts-born computer who worked at the Harvard College Observatory, came along. In 1908, she published a discovery that may sound small but is one of the most important in the history of astronomy. It cracked open the universe.

Before Henrietta Leavitt, many astronomers looked at the stars in whats today known as the Andromeda galaxy some 2.5 million light-years away and mistakenly thought they were part of our own Milky Way galaxy (which is only around 100,000 light-years in diameter).

Those Andromeda stars were orders of magnitude further away. Scientists just didnt know it.

At the time, astronomers had some methods to figure out distances to stars, but they only worked for stars relatively close to Earth. Leavitts discovery linking the pulse of one type of star to their actual brightness, as described in the graphic above was the key to measuring objects farther and farther out into space.

If astronomers wanted to measure faraway things, Leavitts discovery showed, they just had to look out for cepheids. Her formula led astronomers to chart out relative distances to stars: They could use it to compare two stars and figure out which one was closer.

It took some more work by other scientists to calibrate this yardstick, to put concrete numbers on it. But once they did, and started measuring with it, the cosmos grew and grew.

Fifteen years after Henrietta Leavitts discovery, the preeminent astronomers Harlow Shapley and Heber Curtis were locked in a heated debate.

Curtis believed that Andromeda was a separate galaxy far, far away from the Milky Way. At the time, this was an outlandish idea. Shapley represented the more mainstream view that Andromeda was just a hazy, cloudy region within our galaxy, which he had recently estimated to be around 300,000 light-years across. That was also the assumed size of the entire universe.

If Curtis was right, it would mean the universe was double or triple the size that Shapley estimated at least.

To settle the debate, Edwin Hubble the namesake of the famous space telescope looked for Cepheid stars in Andromeda. Night after night, he took photographs of Andromeda, searching for cepheids. In October 1923, he found one, blinking in one of Andromedas spiral arms. Another week of observations allowed him to follow Leavitts formula and determine its distance.

Hubble estimated it to be around a million light-years from Earth well outside the boundaries of Shapleys universe. (Hubble was a little off: Andromeda is closer to 2.5 million light-years away.) After reading about Hubbles finding, Shapley reportedly said: Here is the letter that destroyed my universe.

Scientists kept building on Leavitts ruler to measure the universe. And as they used these measuring tools, their understanding of the universe evolved. They realized it was far bigger than previously thought, there are billions of galaxies, and its expanding: Those galaxies are moving further and further away from one another.

Astronomers also realized that the universe had a beginning. If galaxies are moving away from one another now, it means they were closer together in the past which led scientists to the idea of the Big Bang.

It also led them to realize that the universe may, eventually, end.

This weeks episode of Unexplainable, Voxs podcast about unanswered questions in science, tells that story and more.

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How big is the universe? Henrietta Leavitt led Edwin Hubble to a better, bigger answer. - Vox.com

This illustration depicts a planet partially hidden in the glare of its host star and a nearby companion star. After examining a number of binary stars, astronomers have concluded that Earth-sized planets in many two-star systems might be going unnoticed by transit searches, which look for changes in the light from a star when a planet passes in front of it. The light from the second star makes it more difficult to detect the changes in the host stars light when the planet passes in front of it. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva

Astronomers studying stellar pairs uncover evidence that there could be many more Earth-sized planets than previously thought.

Some exoplanet searches could be missing nearly half of the Earth-sized planets around other stars. New findings from a team using the international Gemini Observatory and the WIYN 3.5-meter Telescope at Kitt Peak National Observatory suggest that Earth-sized worlds could be lurking undiscovered in binary star systems, hidden in the glare of their parent stars. As roughly half of all stars are in binary systems, this means that astronomers could be missing many Earth-sized worlds.

Earth-sized planets may be much more common than previously realized. Astronomers working at NASA Ames Research Center have used the twin telescopes of the international Gemini Observatory, a Program of NSFs NOIRLab, to determine that many planet-hosting stars identified by NASAs TESS exoplanet-hunting mission[1] are actually pairs of stars known as binary stars where the planets orbit one of the stars in the pair. After examining these binary stars, the team has concluded that Earth-sized planets in many two-star systems might be going unnoticed by transit searches like TESSs, which look for changes in the light from a star when a planet passes in front of it.[2] The light from the second star makes it more difficult to detect the changes in the host stars light when the planet transits.

The team started out by trying to determine whether some of the exoplanet host stars identified with TESS were actually unknown binary stars. Physical pairs of stars that are close together can be mistaken for single stars unless they are observed at extremely high resolution. So the team turned to both Gemini telescopes to inspect a sample of exoplanet host stars in painstaking detail. Using a technique called speckle imaging,[3] the astronomers set out to see whether they could spot undiscovered stellar companions.

Using the `Alopeke and Zorro instruments on the Gemini North and South telescopes in Chile and Hawaii, respectively,[4] the team observed hundreds of nearby stars that TESS had identified as potential exoplanet hosts. They discovered that 73 of these stars are really binary star systems that had appeared as single points of light until observed at higher resolution with Gemini. With the Gemini Observatorys 8.1-meter telescopes, we obtained extremely high-resolution images of exoplanet host stars and detected stellar companions at very small separations, said Katie Lester of NASAs Ames Research Center, who led this work.

Lesters team also studied an additional 18 binary stars previously found among the TESS exoplanet hosts using the NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI) on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory, also a Program of NSFs NOIRLab.

After identifying the binary stars, the team compared the sizes of the detected planets in the binary star systems to those in single-star systems. They realized that the TESS spacecraft found both large and small exoplanets orbiting single stars, but only large planets in binary systems.

These results imply that a population of Earth-sized planets could be lurking in binary systems and going undetected using the transit method employed by TESS and many other planet-hunting telescopes. Some scientists had suspected that transit searches might be missing small planets in binary systems, but the new study provides observational support to back it up and shows which sizes of exoplanets are affected.[5]

We have shown that it is more difficult to find Earth-sized planets in binary systems because small planets get lost in the glare of their two parent stars, Lester stated. Their transits are filled in by the light from the companion star, added Steve Howell of NASAs Ames Research Center, who leads the speckle imaging effort and was involved in this research.

Since roughly 50% of stars are in binary systems, we could be missing the discovery of and the chance to study a lot of Earth-like planets, Lester concluded.

The possibility of these missing worlds means that astronomers will need to use a variety of observational techniques before concluding that a given binary star system has no Earth-like planets. Astronomers need to know whether a star is single or binary before they claim that no small planets exist in that system, explained Lester. If its single, then you could say that no small planets exist. But if the host is in a binary, you wouldnt know whether a small planet is hidden by the companion star or does not exist at all. You would need more observations with a different technique to figure that out.

As part of their study, Lester and her colleagues also analyzed how far apart the stars are in the binary systems where TESS had detected large planets. The team found that the stars in the exoplanet-hosting pairs were typically farther apart than binary stars not known to have planets.[6] This could suggest that planets do not form around stars that have close stellar companions.

This speckle imaging survey illustrates the critical need for NSF telescope facilities to characterize newly discovered planetary systems and develop our understanding of planetary populations, said National Science Foundation Division of Astronomical Sciences Program Officer Martin Still.

This is a major finding in exoplanet work, Howell commented. The results will help theorists create their models for how planets form and evolve in double-star systems.

Notes

This research is presented in the paper Speckle Observations of TESS Exoplanet Host Stars. II. Stellar Companions at 1-1000 AU and Implications for Small Planet Detection to appear in the Astronomical Journal.

Reference: Speckle Observations of TESS Exoplanet Host Stars. II. Stellar Companions at 1-1000 AU and Implications for Small Planet Detection by Kathryn V. Lester, Rachel A. Matson, Steve B. Howell, Elise Furlan, Crystal L. Gnilka, Nicholas J. Scott, David R. Ciardi, Mark E. Everett, Zachary D. Hartman and Lea A. Hirsch, Accepted, Astronomical Journal.arXiv:2106.13354

The team is composed of Kathryn V. Lester (NASA Ames Research Center), Rachel A. Matson (US Naval Observatory), Steve B. Howell (NASA Ames Research Center), Elise Furlan (Exoplanet Science Institute, Caltech), Crystal L. Gnilka (NASA Ames Research Center), Nicholas J. Scott (NASA Ames Research Center), David R. Ciardi (Exoplanet Science Institute, Caltech), Mark E. Everett (NSFs NOIRLab), Zachary D. Hartman (Lowell Observatory & Department of Physics & Astronomy, Georgia State University), and Lea A. Hirsch (Kavli Institute for Particle Astrophysics and Cosmology, Stanford University).

NSFs NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRCCanada, ANIDChile, MCTICBrazil, MINCyTArgentina, and KASIRepublic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (operated in cooperation with the Department of Energys SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Duag (Kitt Peak) in Arizona, on Maunakea in Hawaii, and on Cerro Tololo and Cerro Pachn in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono Oodham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

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Are We Missing Other Earths? Dramatic New Evidence Uncovered by Astronomers - SciTechDaily