Category Archives: Astronomy

Messier 5 is a large, bright and beautiful globular cluster, making it a show-stopping object for the late spring. Image: Ronald Brescher.

Messier 5 in Serpens Caput is a dynamic and beautiful globular cluster that can easily be spotted through a pair of binoculars and fruitfully observed through even a moderate-sized telescope. Globular clusters are extremely luminous, spherical conglomerations of up to a million stars crammed into a space spanning between just tens to perhaps 200 light years. This makes them among the most densely packed stellar systems in the Universe. Not only are globulars marvellous objects to observe, but they provide much food for thought as you gaze upon their sheer majesty, with the vast majority of them believed to be nearly as old as the Universe itself.

At this time of the year, the prime-time night sky is brimming with some of the best globulars of all, including mighty Messier 13 in Hercules, Messier 3 in Canes Venatici and a whole sackful in nearby Ophiuchus. The good news is that M5 comfortably holds its own with the fierce competition.

From pristine dark-sky sites, Messier 5 (NGC 5904, magnitude +5.7) is faintly visible with the naked eye, lying 22 arcminutes north-north-west of the star 5 Serpentis (HIP 74975, magnitude +5.4). Remember to look for M5 in Serpens Caput and not Serpens Cauda; the former lies to the south-west of Hercules, while M5s environs border Virgo.

As darkness falls on an early June evening, M5 can be seen at an altitude of around 40 degrees high to the south from mid-northern latitudes, soon destined to transit the southern meridian at around 11.50pm BST.

Messier 5 shows up as an unresolved patch of light through 10 x 50 binoculars, but a telescope as modest as 75 or 80mm (~three inches) in aperture has sufficient revolving power to pick out the clusters more outlying stars. It can also show that M5 is ever-so slightly elliptical in shape, with its concentrated core offset mainly to the east and slightly to the north. Upgrade to a 150200mm (six- to eight-inch) telescope for a truly memorable view; on a steady and transparent night, when you can push the magnification, you should be able to see (resolve) individual stars across a roughly 10 arcminute-sized sphere and more or less all the way down to M5s core.

M5 makes an epic imaging target, especially for long focal length telescopes. Its overall bluish nebulous haze, which expands to between 17 and 23 arcminutes (depending where you look in the literature), is liberally sprinkled with beautifully contrasting golden suns.

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Messier 5's big appeal in early summer's globular feast Astronomy Now - Astronomy Now Online

Students keen to pursue astronomy and physics research can enrol for a seven-week programme hosted by Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune. The last date for sending online applications for the VSP is May 31.

Students who have completed their first-year M Sc, either in physics, applied mathematics, astronomy, electronics or scientific computing, are eligible to apply for the Vacation Students Programme (VSP). Besides, third-year bachelors of technology or engineering and those in the third or fourth year of the integrated M Sc programme can also send applications. The last date for sending online applications for the VSP is May 31.

During the programme, students will be mentored by scientists. They can also take part in seminars and pursue projects.

The IUCAA will pay the participating students a stipend of Rs 10,000 along with free on-campus accommodation and travel allowance by train. Enquiries can be sent to aocp@iucaa.in.

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Pune: IUCAA to offer 7-week vacation programme in astronomy, application closes on May 31 - The Indian Express

The Hydrogen Epoch of Reionisation Array in the Northern Cape. (Image credit: SARAO)

South Africas Hydrogen Epoch of Reionisation Array (HERA) telescope has attracted over R74 million direct financial investment since 2013.

This is according to the South African Radio Astronomy Observatory (SARAO), which has undertaken a local impact study of SAs hosting of HERA.

The HERA telescope is an array of 350 antennas situated next to the MeerKAT radio telescope on the site that hosts the Square Kilometre Array in the Northern Cape.

HERA is a US-led project that forms part of a large international collaboration representative of institutions from Europe, SA, the UK and US.

The goal is to observe how the first structures formed in the very early stages of the Universe, as the first stars and galaxies lit up space.

Construction of the telescope began in 2015, with the full array reaching completion in 2021.

SARAO managed the construction of the infrastructure in close collaboration with US institutions. The instrument is now undergoing commissioning and validation of its data.

The findings from the financial assessment of the impact study indicate the total direct investment made towards the HERA project is well over R70 million (R74 090 948), which was invested by the three countries from 2013 to 2021.

This represents the annual direct investment towards HERA from all contributing countries. An increase in the direct financial investment is observed from 2015, which marks the start of construction of the instrument in SA.

The maximum annual direct financial investment occurred in 2018 (R23 409 564; ie, 32% of the total direct financial investment) at the peak of the construction efforts, with the annual direct financial investment tapering off as the project neared completion over the period 2019 to 2021, says SARAO.

It notes the findings from the HERA impact study indicate SA received substantial direct foreign investment for construction of the infrastructure.

Most of the investment towards infrastructure went to the Northern Cape, with materials sourced from local suppliers during construction of the infrastructure.

At a regional level, it was found that Carnarvon benefitted most from the investment when compared to other towns in the province.

The findings demonstrate how international investment in astronomy research infrastructure can stimulate economic development to benefit the region closest to the infrastructure.

With a creative approach and some careful considerations, the smaller, less technically stringent projects can be successfully executed (parts manufactured and supplied, labour sourced and managed) all using the resources available in the Northern Cape, says Ziyaad Halday, SARAO project manager for HERA.

This strategy facilitates employment and spending in sectors that are not the provinces main financial drivers, such as mining and agriculture.

South Africa, through SARAO, has contributed significantly to the HERA collaboration by providing the human resources required for managing the project locally, and employing the workers needed for building, operating and maintaining the infrastructure.

Over the course of seven years, SARAO says the construction of HERA on the telescope site has created employment for 24 individuals, who were mostly recruited from Carnarvon.

It says the co-hosting of astronomy infrastructure such as HERA can have additional benefits for local communities through employment opportunities that arise from construction of the instrument to the maintenance needed following the construction phase.

South Africa has become a destination of choice for the hosting of international astronomy infrastructure, says Dr Bonita de Swardt, SARAO programme manager for strategic partnerships for human capital development and author of the report.

This includes smaller astronomy telescopes, instruments and experiments in astronomy that can be easily plugged into the existing infrastructure on operational sites.

HERA represents only one of these co-hosted instruments for an international collaboration of scientists. The impact study shows how SA can benefit from smaller scale, co-hosted instrumentation through business development, to the employment it can create for people living in some of the most impoverished and rural geographical areas in the country.

On a national level, the impact study found there is growing participation of South African researchers in the HERA collaboration.

This was mainly a result of continuous financial support towards masters and doctoral scholarships, in conjunction with the award of postdoctoral research fellowships supported by SARAOs human capital development programme and collaborating universities, the organisation says.

These initiatives were supported throughout the construction of HERA, which has led to increased participation of researchers based at local universities in the collaboration, ensuring SAs representation in world-class research conducted with this instrument, it concludes.

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HERA telescope shows benefits of radio astronomy in SA - ITWeb

Two First Nations astronomers are working to show Indigenous children they can pursue their astronomy dreams through an Australian National University program.

The ANU last week hosted a week-long program with Indigenous high school students from remote regional NSW and Tasmania to give them first-hand experience of Indigenous astronomy.

Hosted at the Mt Stromlo Observatory in Canberra, the program provided year 10 and 11 students with a chance to work with ANU masters students, Gamilaraay-Yuwaalaraay man Peter Swanton and Gamilaroi astronomer and science communicator Karlie Moon.

Being mentored by professional astronomers, students built smart phone devices to measure the chemical make-up of light and undertook remote observation at Siding Spring Observatory.

Weaved through the program was an exploration of Indigenous interpretations of the night sky to inform navigation, calendars, and predicting the weather.

ASTRO 3D education and outreach manager Delese Brewster was designed to inspire the next-generation of First Nation astronomers, researchers and scientists.

This group is under-represented in astronomy and we need to provide a pipeline that will encourage Aboriginal and Torres Strait Islander students into tertiary study, she said.

Mr Swanton said the program improved visibility for Indigenous children interested in the field.

I never had this when I was going through school, he said.

It felt quite disengaging when I went to high school, as I had no role models.

I never had someone in front of me, that looked like me, that talked like me

Mr Swanton said he enjoyed seeing children take part in the program.

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Indigenous astronomers helping next-gen First Nations scientists reach for the stars - National Indigenous Times

We now know of more than 5,000 exoplanets beyond the solar system. What we really understand about each of these worlds, though, is barely anything at all. Most of them have been seen only indirectly from their shadows as they cross in front of the stars they orbit. The few that researchers have managed to actually take a picture ofthat is, to directly image using light emanating from the planets themselvesappear as little more than monochromatic dots even in the very best current telescopes. And so far all of those directly imaged worlds are among the brightest, largest and least Earth-like exoplanets known.

The far future may be a different matter. How detailed could a picture of a distant exoplanet beespecially one that is small and rocky like Earth? The answer is that someday astronomers could obtain images revealing continents, clouds, oceans, ice caps and even vegetation on some remote Earth-like world orbiting an alien star.

The problem is that the most powerful telescope for this task cant be builtnot exactly, anyway. Instead it must be conjured into existence using the tenets of Einsteins general theory of relativity to transform our sun itself into a star-sized magnifying glass. Albert Einsteins key insightthat gravity can be understood as the curvature of spacetimemeans that stars and other massive objects act as natural gravitational lenses that warp and amplify the light from background objects.

Astronomers today routinely use galaxies and galaxy clusters as gravitational lenses, but the prospect of using this technique for our sun poses so many challenges that few researchers have taken it seriously. Most notably, the approach requires precisely positioning a conventional telescopesomething like Hubble, for instanceat the point where any given targets lens-amplified light comes to a focus. For the sun, those focal points are found at the extreme outskirts of the solar systemat least 14 times farther out than Pluto.

Now a new study by astronomers at Stanford University shows that a simplifying shortcut could exist for the still arduous task of imaging exoplanets using our sun as a cosmic telescope. The study, published in the Astrophysical Journal, suggests astronomers could eventually achieve exoplanet imaging with a resolution 1,000 times greater than that of the Event Horizon Telescope, which has been used to capture the historic first images of supermassive black holes. Its just neat to think of this as kind of the ultimate end game of the process of studying exoplanets, says Bruce Macintosh, a Stanford astrophysicist, who co-authored the paper, or at least the end game short of actually visiting them.

Alex Madurowicz, Macintoshs co-author and graduate student, first fed real satellite images of Earth into a computer model that reduced our world to how it might appear if it was seen from afar through a stellar gravitational lens. In most circumstances, the resulting image would be an Einstein ringa distorted, circular smear produced by the planets light curving around the lensing star. Earlier work by another researcher, Slava Turyshev of NASAs Jet Propulsion Laboratory, had shown that correcting those distortions would require methodically moving a light-gathering conventional telescope back and forth within the focal region at the solar systems edge. The resulting pixel-by-pixel scan of the planets warped projection, somehow choreographed from Earth upward of 80 billion kilometers away, could take thousands of hours and consume enormous amounts of fuel.

Madurowicz and Macintosh realized that this harsh calculus could change, however, given that the sun is slightly oblong rather than perfectly spherical. That minor detail means that if the target exoplanet aligns perfectly with the suns equator as seen from the focal-region telescope, the product is not an Einstein ring but a crossfour asymmetrical copies of the planet around the suns perimeter. Madurowicz found that, by exploiting this asymmetry, the scanning process to reconstruct a target exoplanets undistorted image could be eliminated. You dont have to move [your telescope] around inside the image, he says. You can just stay in one spot.

Turyshev, who was not a part of this latest study, is skeptical that the painstaking process of scanning he first described can actually be eliminated. The idealized technique for image reconstruction that Macintosh and Madurowicz propose, he says, would have to overcome possible interference arising from the brightness of our sun and its seething outer atmosphere, known as the corona. It would be nice if the sun would just be dark, right? Turyshev says. But it is not, of course, and even the best equipment could not fully block a fraction of it from trickling into a telescope, especially one staring directly at our star. Their paper is wonderful, but its a theory, he adds.

Even if the scanning process could be eliminated, there are other limitations to consider as well. Each exoplanet targeted for solar gravitational lensing would likely require its own dedicated Hubble-like space telescope sent to and operated at the solar systems outer limits. For example, for such an observatory to image a second exoplanet just 10 degrees off from its original target, it would need to shift its position around the sun by more than 14 billion kilometers. To use a solar gravitational lens, you need to line up the telescope, the sun and the planet extremely precisely, Madurowicz says. There would be no way for a single telescope to image more than one planet, or one star system with several interesting worlds, at a time.

This limitation is the reason Jean Schneider, an astronomer at the Paris Observatory, has his eye on a different, perhaps more feasible alternative to solar gravitational lensing: the hypertelescope. This broad concept envisions the detection of surface features of exoplanets through the use of space-based fleets of many meter-scale mirrors flying in formation to create virtual telescopes larger than any single one ever could be. Schneider agrees direct images of potential extraterrestrial vegetation would be precious and would provide insights unavailable through any other known method of remote observation.

Aki Roberge, an astrophysicist at NASAs Goddard Space Flight Center, points out that astronomers dont even know if there is another world like our own out there at all. Not just Earth-size, she says, but Earth-like, with oceans, continents, an atmosphere and a biosphere. And direct imaging, it seems, is the only way to really find out.

A proposed observatory recommended in the National Academies of Sciences, Engineering, and Medicines report Pathways to Discovery in Astronomy and Astrophysics for the 2020s, otherwise known as the Astro2020 Decadal Survey, may offer the best near-term hope of giving Roberge and her peers the answers they need. The survey serves as a once-a-decade roadmap guiding U.S. astronomy. And topping its latest roadmap is a concept for a space telescope with a mirror more than six meters wide, something of a super Hubble tuned for gathering optical, infrared and ultraviolet light that is intended for launch as soon as the early 2040s.

According to Astro2020s recommendations, one of the core capabilities of such a telescope would be directly imaging a diversity of exoplanets with the key objective of studying their atmospheres to make better guesses about their environmental conditions. From there, astronomers might determine if the chemical necessities or by-products of life as we know it water, organic compounds, free oxygen, and so onexist on any of the targeted worlds. The fuzzy blobs that might be imaged by this proposed telescope could be the first small step toward truly knowing an exoplanets potential to harbor life. Only after such a mission, most astronomers say, could we make the giant leap of building a hypertelescope or exploiting the solar gravitational lens to get detailed surface images. We have a path to the 2040s. After that, its the Wild West, Roberge says.

Despite the far-out nature of the solar gravitational lens, Turyshev, Macintosh and Madurowicz are of one mind: thinking about its possibilities now is worthwhile. Already, advances in solar sails and other unconventional propulsion technologies offer the possibility of expediting the requisite journey to the solar systems outermost reaches. The challenges remain daunting, but using our star as the ultimate telescope may be closer to reality than anyone now suspects. By anticipating the theoretical and practical limits of the approach, whenor ifit finally lies within our grasp, the question will not have to be Can we do this? but rather What planets should we image?

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Our Sun Could Someday Reveal the Surfaces of Alien Earths - Scientific American

Astronomers have uncovered the first solid evidence that merger events between black holes can deliver a "kick" powerful enough to send a black hole spinning out of its galaxy.

The team, which included Vijay Varma, a physicist at Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Germany, examined gravitational-wave data from the merger event known as GW200129 collected by the LIGO detectors and their European counterpart, Virgo. Through that analysis, the scientists discovered that the black hole created in that collision and merger had been sent hurtling through space at 3 million mph (4.8 million kph) a finding described by one team member as "both surprising and shocking."

"When two black holes collide, they leave behind a more massive, remnant black hole. This process can impart a recoil 'kick' to the remnant black hole," Varma, lead author of a paper detailing the team's work, told Space.com.

Related: 8 ways we know that black holes really do exist

When black holes orbit each other, they emit gravitational waves essentially gravitational radiation that carry away energy and angular momentum as they ripple through the fabric of space. These emissions cause the orbit to shrink, leading to a collision and merger of the black holes.

If the black holes have unequal masses or spins, however, this leads to an asymmetry in the emission of gravitational waves, with them being primarily emitted in one direction. Because the basic laws of physics require that momentum has to be conserved, this asymmetry results in a large kick, causing the remnant black hole to recoil in the opposite direction.

"Black hole mergers also emit gravitational radiation, similar to astrophysical processes that emit electromagnetic radiation light," Varma continued.

These large kicks are expected when the merger's orbital plane precesses, or "wobbles." Orbital precession is observable as a small amplitude modification in the gravitational-wave signal. "This binary black hole system is also the first signal showing strong signs of orbital precession, whereby the orbital plane wobbles," co-author Scott Field, a mathematician at the University of Massachusetts Dartmouth, told Space.com.

Varma added that by analyzing gravitational radiation, astronomers and astrophysicists can learn about black-hole mergers. Additionally, because black holes are influential in the evolution of the galaxies, learning more about these processes could reveal how collections of stars like the Milky Way develop.

This is the first time astronomers have collected strong evidence that such a merger can eject the resulting black hole from its galaxy.

"Unlike previously observed black hole merger events, this is the first one to provide strong evidence for enormous recoil velocity. Large enough, in fact, for the remnant black hole to most likely escape from its host environment," Field said. "While we knew general relativity allowed for such extreme possibilities in principle, we did not know if the universe would produce them. The final black hole's speed is sufficiently large that it most probably exceeds the escape velocity of its host environment."

Field added that this result will have important implications for binary black hole formation scenarios, too. This is because supermassive black holes, like Sagittarius A* (Sgr A*) at the heart of the Milky Way, form through a series of collisions that scientists call hierarchical mergers. Black holes kicked from a galaxy can't partake in this process.

The discovery of mergers lopsided enough to give black holes a powerful kick is now possible thanks to technology that allows for more precise detections of gravitational waves.

"Black hole mergers don't emit any light, so gravitational waves are the only way to observe and learn about them. We would not know about this ejected, rogue black hole without gravitational wave observatories," Field added.

Scientists aren't precisely sure where the gravitational wave event GW200129 originated, so Field points out that the team can't completely sure the black hole was ejected from its galaxy, but this is the probable outcome of it moving at such extreme speeds, according to the researchers.

"If that is indeed the case, it is now roaming around the universe by itself as a rogue black hole," Varma said.

The merger that occurred here may be a miniature version of an even more dramatic event, he noted. "A similar phenomenon happens when supermassive black holes merge, which can happen after a galactic merger," Varma said. "The final supermassive black hole can get displaced from the center of the merged galaxy, or even ejected from it, leaving behind a galaxy without a central black hole."

Although existing gravitational-wave detectors are not quite powerful enough to observe supermassive black hole mergers, the authors added that future space-based detectors like the proposed Laser Interferometer Space Antenna (LISA) mission, might be able to.

"Gravitational-wave astronomy has delivered many high-impact, truly remarkable discoveries over the past five or so years," Field said. "Before the first detection of gravitational waves, the mantra of our field had been that gravitational waves will open a new window on the universe. And this has proven to be true with each and every new LIGO observing run."

The research is described in a paper (opens in new tab) published May 12 in the journal Physical Review Letters.

You can follow Rob Lea on Twitter at @sciencef1rst. Follow us on Twitter @Spacedotcom (opens in new tab) and on Facebook (opens in new tab).

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A black hole formed by a lopsided merger may have gone rogue - Space.com

One of the last places in the Universe you want to find yourself is next to a supernova. When a star explodes, the energy released is mind crushing: They can be 10 billion times as luminous as the Sun, literally outshining all the other stars in a galaxy combined. The chaos and mayhem are absolutely brutal, and its difficult to believe anything could survive it.

Yet a relatively new hypothesis is that something can: A binary companion star, one that orbited the supernova progenitor before it exploded, and that may play a crucial role in the star going supernova in the first place. And now just such a companion star may have been found in Hubble images, one that survived the explosion and may still be reeling from the effects [link to paper].

In November 2013 the light from the supernova reached Earth. Called SN2013ge, it came from the explosion of a star in NGC 3287, a spiral galaxy in the constellation of Leo. Its whats called a core collapse supernova, when a massive star runs out of fuel at the end of its life. The stellar core collapses, sending out a vast blast of energy that blows away the stars outer layers, accelerating them to a decent fraction of the speed of light.

But it was a weird one. Normally, the outer layers of a star are almost entirely hydrogen, so when we take spectra of the supernova we see lots of hydrogen in it. But theres a class of core collapse supernovae that does not show hydrogen. The thinking is that in the last stages of its life, the star blew away its outer layers in a fierce wind, and that material is lost to space before the star explodes. These are called stripped supernovae. SN2013ge was clearly this kind of supernova.

We do see stars blasting away their outer layers called Wolf-Rayet stars, theyre nearly as terrifying as supernovae but observations of supernovae dont quite jibe with this idea. So astronomers turned to a different hypothesis: The supernova progenitor star wasnt alone, but was instead in a binary system.

If it had a companion star, things change. When the progenitor starts to die, it swells up into a huge red supergiant. This happens whether the star is single or not; examples include Betelgeuse and Antares, both so luminous theyre among the brightest stars in the sky despite their great distance from us.

But if theres another star there in a close orbit around it, the red supergiant will dump a lot of its outer layers onto this other star instead of losing them to space. The second star accumulates this matter mostly hydrogen and can gain a lot of mass. When the first star explodes we dont see hydrogen in it because its all on the other star.

This changes what we see. The supernova fades over time, but the light from the second star doesnt, so we should see a huge brightening during the explosion, then a fading, but then it levels off after a few years due to the second stars steady light. Also, you expect to see a lot of ultraviolet light from the event as the hell fury of the supernova slams into the second star, creating an immense and powerful shock wave.

And thats just whats seen from SN2013ge. The astronomers proposed using Hubble Space Telescope specifically to observe stripped supernovae to look for evidence of a companion star, and found it in this case. Looking at SN2013ge for years after the event, they find the light from the explosion had faded but right next to it was a steady source that did not fade. They also saw two bright peaks in ultraviolet light during the supernova itself, indicating they were seeing UV from the explosion as well as the shock wave as material blasted the second star.

This is the first time such evidence has been found in a stripped supernova. To be fair, there could be other reasons this was seen; perhaps the second source is a small, unresolved cluster of stars that hosted the progenitor. It would have to be unusually small, though, and the astronomers assign only a 10% chance this is the case. It could also be material previously ejected from the progenitor star getting whacked by the exploded material, but the colors of the light make this unlikely as well.

If the second source is truly a companion star, then its weird too: The light indicates its a B5 supergiant, an immense and truly massive star late in its life. That would be expected if it ate a lot of the other stars material, but its also a lot redder than expected for such a star. That could be due to it still recovering from all that hydrogen dumped on it before the first star exploded, though.

More observations, as always, are needed. And not just of SN2013ge but also of other stripped supernovae. The good news is that these do happen often enough to spot, and we do tend to get observations of them early on as well as monitor them for many years. And if the SN2013ge second source is actually a B5 supergiant, then it too will eventually explode. Maybe not for many years, or even centuries, but who knows? We may get lucky if we keep watching these ridiculously powerful events.

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Bad Astronomy | SN2013ge indicates a companion star may have survived the blast - Syfy

image:Recipients of the 2022 Shaw Prize in Astronomy Lennart Lindegren and Michael Perryman. view more

Credit: Shaw Prize

Hipparcos, launched in 1989, measured the positions and motions of over 100 000 stars with an accuracy two orders of magnitude better than ground-based observatories. Gaia, launched in 2013 and still operating, has measured the positions and motions of billions of stars, quasars and Solar System objects with even higher accuracy. The results from these missions offer an exquisitely detailed portrait of the distribution and properties of the stars in our Galaxy, as well as unique insights into its formation and history, and they impact almost every branch of astronomy and astrophysics. This award is also intended to honour the much larger community of astronomers and engineers who made Hipparcos and Gaia possible.

The measurement of the positions, distances and motions of planets and stars has been central to astronomy since prehistoric times. The early naked-eye star catalogues of Ptolemy (ca. 100170 CE), Ulugh Beg (13941449) and Tycho Brahe (15461601) were supplanted in the last two centuries by telescopic catalogues of ever-increasing size and accuracy. However, by the late twentieth century, astrometry from ground-based optical telescopes encountered insurmountable barriers to further improvements, arising from atmospheric distortions, thermal and gravitational forces on the telescopes, and the difficulties of stitching together data from different telescopes.

The era of precision space astrometry began with the European Space Agencys Hipparcos mission (19891993). Hipparcos catalogued over 100 000 bright stars. It measured annual changes in the apparent position of these stars on the sky as small as the width of a human thumb in Beijing as viewed from Hong Kong. By measuring small variations in stellar positions as the Earth travelled around its orbit (parallax), Hipparcos determined distances to over 20 000 stars with uncertainties of less than 10%.

ESAs Gaia mission, launched in December 2013, is based on the same design principles as Hipparcos, but has vastly greater capabilities. Gaia has measured the positions of 10 000 times as many stars as Hipparcos with an accuracy 100 times greater. Gaia has catalogued almost one per cent of all the stars in the Milky Way, and so far has measured parallax-based distances to over 50 million stars with uncertainties of less than 10%. Such parallaxes are the foundation of all distances in astronomy and thus are the firmest foundation we have for measuring the scale of the Universe.

The study of the preliminary catalogues released by the Gaia project, all of which are in the public domain, has already transformed many areas of astronomical understanding. Even richer, larger and more accurate catalogues will be produced before the mission is completed in 2025 or later. Gaia is providing a survey of our Galaxy that will not be surpassed in quantity or quality for decades to come.

Gaia can measure changes in the positions of stars on the sky as small as the width of a human hair in Beijing as viewed from Hong Kong, and motions on the sky smaller than the apparent rate of growth of a hair belonging to an astronaut on the Moon, as seen from Earth. This remarkable performance is achieved by a unique architecture consisting of two telescopes pointing in very different directions, whose images are combined on a single detector. The telescope spins once every six hours, and sends back to Earth precise measurements of the times at which the stars cross a fixed point on the detector.

Why is accurate astrometry so important? The answer is that it provides fundamental data positions, velocities, and distances that underpin almost every aspect of modern astronomy and astrophysics. Accurate distances to stars allow us to measure their intrinsic luminosities, and this in turn is a sensitive measure of their internal physical processes, such as crystallisation in the interior of degenerate stars. Small-scale inhomogeneities in the spatial distribution of stars provide a glimpse of disrupted clusters of stars, perhaps similar to the one in which the Sun was born. Measurements of the velocities of stars allow us to infer their Galactic orbits, which in turn provide clues to the formation history of the Milky Way and the distribution of the mysterious dark matter within it.

Gaia is detecting debris from small satellite galaxies that were disrupted long ago by the Milky Way, as well as irregularities in the distribution of stars in the Galactic disc that may reflect recent disturbances from surviving satellite galaxies or unseen clumps of dark matter. Gaia measurements have for the first time allowed us to determine the orbits of distant star clusters and dwarf galaxies. Gaia will provide a rich harvest of ancillary astronomical results, including an all-sky multi-colour photometric survey of a billion stars; radial velocities of many millions of stars; light curves for hundreds of thousands of variable stars; the discovery and measurement of thousands of extrasolar planets; a survey of asteroids and other small Solar System bodies in unprecedented detail; a uniform catalogue of hundreds of thousands of distant quasars; and stringent new tests of Einsteins theory of gravity.

Hipparcos and Gaia succeeded because of the collective efforts of many people lasting over half a century. The Shaw Prize recognises two of these individuals who have made sustained key scientific contributions to the two missions. Lennart Lindegren originated many of the concepts of the Hipparcos mission design and was leader of one of the two independent teams that carried out the data analysis for Hipparcos. He was a member of the Hipparcos science team for two decades and the Gaia science team for two decades after that. Michael Perryman was Project Scientist for Hipparcos from 1981 to 1997, Chair of the Hipparcos Science Team for the same period, and lead author on the 1997 paper describing the Hipparcos catalogue. Perryman was also Project Scientist for the Gaia mission from 1995 to 2008, Chair of the Gaia Science Advisory Group from 1995 to 2000, and Chair of the Gaia Science Team from 2001 to 2008. Lindegren and Perryman proposed the concept for Gaia in the 1990s and were instrumental in its scientific and technical design.

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The IAU is the international astronomical organisation that brings together more than 12 000 active professional astronomers from more than 100 countries worldwide. Its mission is to promote and safeguard astronomy in all its aspects, including research, communication, education and development, through international cooperation. The IAU also serves as the internationally recognised authority for assigning designations to celestial bodies and the surface features on them. Founded in 1919, the IAU is the world's largest professional body for astronomers.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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Lennart Lindegren and Michael Perryman receive the 2022 Shaw Prize in Astronomy - EurekAlert

Among our crosswords and other puzzles, well be featuring logic challenges from Puzzle Communication Nikoli, a cult-favorite puzzle publication from Japan. A PDF of the puzzle, as well as the solution, can be downloaded below.

Gesaku got his ideas from the things that he saw around him every day: the design of floor tiles on a subway platform or the ripples in a pond. Gesakuthe only name by which he is knownwas a dedicated reader of Japans Puzzle Communication Nikoli, the most influential puzzle publication in history. Nikoli is famed not just for making Sudoku a household name, but also for being created almost entirely by fans like Gesaku.

Many of those readers submit hand-crafted examples of existing puzzles. Gesaku was one of the rare readers who created his own, and he was one of Nikolis most prolific. More than 30 of his original puzzles have been chosen for publication; only two or three creators have managed this feat in Nikolis more than four decades of publication.

Shapes and mathematical regularity were Gesakus muses, according to Nikoli president Yoshinao Anpuku. Anpuku had spoken with Gesaku in the past, but the magazine has lost touch with him, and its unknown if hes still making puzzles.

Gesakus Tentai Show debuted in 2001 as a logic puzzle based on filling a grid with symmetrical shapesrecalling origami, celestial bodies such as galaxies and stars, and traditional Japanese clan symbols. The puzzle was modestly received at first, but six months later Gesaku came up with an idea that made Tentai Show one of Nikolis most beloved reader creationsusing solving logic to create a picture, making each one a kind of puzzle-based constellation.

This connection with the celestial is reinforced in the puzzles pun-based name. The Japanese word ten-taisyo means symmetry about a point, while the word tentai means heavenly body, such as a star, writes author Alex Bellos in his book about Japanese logic puzzles, Puzzle Ninja. Tentai Show is thus an anglicized pronunciation of point symmetry with a double meaning of astronomical show.

A Tentai Show consists of a grid with scattered dots. The goal is to divide the entire grid into regions, each containing a single dot. Each region must have rotational symmetry, meaning that it must form the same shape when rotated 180 degrees around the dot at the center of the region. (For example, the letter S and rectangles have this symmetry; E does not.)

Since no region can contain two dots, one way to start is to draw a line between any squares that contain a dot or a fraction of one. These segments start to form the outlines of the regions. To fill in the rest of the outlines, you will need to mentally rotate the segment 180 degrees around each dot. For example, a top edge must be matched by a bottom edge, a left by a right. Remember that the sides of the grid are part of the outlines of the regions, too. As you start to fill in the grid, you will see that the positions of the dots force a unique arrangement of regions.

To complete the puzzle and see the final image, shade in all the regions that contain a black dot at the center.

In the downloadable PDF below, youll find the instructions above, an example, three puzzles of increasing difficulty, and an Atlas Obscura surprise.

Stumped? Download the solutions!

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Puzzle Monday: Logic, Symmetry, and Astronomy - Atlas Obscura

Nassau Community College's former observatory is looking for a new home, and a group of amateur astronomers hopes it could become New York City's first for-the-public observatory.

The Garden City school closed the 12-foot-high, 6-foot-wide observatory at the end of 2019 as it prepared for renovations. The structure, which was used by astronomy students for more than 40 years, is being replaced by a green roof and six open-air telescopes.

Local astronomers and professors are scrambling to move the half-ton galvanized steel observatory off the campus by May 24th and find it a new home.

I couldn't let it go to the scrap, and I even wanted it if I didn't have a bunch of trees in my yard, Id plop it in the middle of my yard, said Dr. Thomas Bruckner, chair of Physical Sciences at the college. But a lot of people wanted it, it was just a matter of picking it up. It's big and heavy. It doesn't come apart.

The Amateur Astronomers Association of New York is leading the mission, and after a nearly yearlong journey, it may have settled on a permanent home in the Bronx. The old observatory could see past the Andromeda Galaxy, more than 2.5 million light years from Earth, on a clear, dark night so a public space offers a unique opportunity for young aspiring astronomers to explore the cosmos.

The final frontier is just within reach if city park officials can agree to the plan in time.

Over nearly 200 years, several stargazers have tried and failed to set up the city's first public observatory, according to the International Planetarium Society. The closest alternatives are at Columbia University and various City University of New York campuses, including one shuttered on top of Ingersoll Hall at Brooklyn College. All of which are prioritized for their students.

The latest quest has likewise felt long, since the Amateur Astronomers Association took on the challenge of moving the Nassau Community College observatory in May 2021. But the association doesnt want to move the structure to a temporary home only to have to pay for a second move.

Bart Fried, the organizations executive vice president and a telescope historian, said each move would cost more than $3,000, depending on the distance, because a boom truck is required.

The first location that came to mind, in July 2021 when amateur astronomers began planning, was Floyd Bennett Field in Brooklyn. Its dark, and the organization has been running the parks stargazing programs for more than 40 years. But they were turned down after more than three months because of historical preservation issues, according to Fried, and the search continued.

The next site was about seven miles up the Belt Parkway. Shirley Chisholm State Park is built on a Brooklyn landfill and is a treeless stretch of prairie grassland perfect for stargazing with no obstructions.

There was one hitch. The park closes at 7 p.m., and that doesnt work for summer when it isnt fully dark until after that time.

After Shirley Chisholm [State Park] turned us down, we were feeling pretty defeated at this point, said Kat Troche, a member of the NASA Solar System Ambassador program involved in relocating the public observatory. Wow, we can't even give this thing away.

The Amateur Astronomers Association was willing to provide the programming and staffing and pay for installation, upkeep and retrofitting including theft and defacement. According to Fried, the giant structure doesnt require a foundation, and therefore no concrete work is needed in order to relocate/situate the observatory. Aside from putting metal rods into the ground to hold the observatory down, no digging will be required either. To level the structure, it needs to sit on about 6 inches? of wood decking, which will be hidden by the domes skirt. And access to utility lines isnt necessary because it will be powered by battery packs charged by solar panels.

This is super important [to have a public observatory in New York City]. One of our events could inspire future astronauts, future cosmologists, and astrophysics, Troche said. The stars it's something to aspire to. We have this natural urge to wander and the cosmos allows us to do that.

The observatory still had no solid option for a home until one fall evening in 2021. While hosting a sidewalk astronomy event near The Bronx High School of Science, it dawned on the members of the Amateur Astronomers Association that they were standing in the perfect location.

We dont do enough in the Bronx. Why dont we put the dome up there where the public can use it; and Bronx Science can use it and we can use it? Fried remembered thinking at the time. It will be New York Citys very first truly public observatory even though there have been attempts over 150 or 200 years, all of which failed for various reasons, including several attempts in Central Park.

The location is across Goulden Avenue from The Bronx High School of Science on the grassy banks along the Jerome Park Reservoir. The school also has a planetarium, and a very active astronomy club headed by the schools physical science teachers Neil Farley and Colin Morrell. School administrators have approved the plan, but it still needs sign off from city officials.

Currently, city park officials are reviewing plans for a resting place in Jerome Park, according to email correspondence shared with Gothamist.

We are in close contact with the Amateur Astronomers Association on the relocation of the observatory, and are looking into the potential of re-homing it in one of our parks, wrote Dan Kastanis, a press officer at New York City Parks Department. No plan has been finalized at this time.

While the goal is to move the observatory to its new home before Memorial Day, the parks department called their process not straight-forward with many logistical, legal and permitting issues that must be worked out first. That includes figuring out accessibility for people with disabilities, graffiti prevention and the installation process.

In the meantime, theres still a possibility that parks approval wont come in time for the observatorys eviction from Nassau Community College on May 24th. If that happens, the Amateur Astronomers Association has a backup plan. It will need to find a way to temporarily move the 360-degree rolling-top dome less than a half-mile away to the Cradle of Aviation Museum in Garden City, New York where it will be cleaned and repainted.

Despite the hassle, the several astronomers involved are determined to make this observatory accessible to anyone curious enough to gaze into the cosmos.

Of all the sciences, astronomy is the least resolved. We only know what 4% of the matter in our universe, we don't know what the rest is, Bruckner said. It's the next generations of the curious that will lead us into discovering what our universe is made out of how and why we came to be.

If all goes well, the Amateur Astronomers Association plans to celebrate the opening of the New York City Public Observatory this summer in a permanent Bronx home. The festivities would include a first-light party, a tradition that marks the initial viewing through a new telescope.

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NYC's first public observatory is running out of time to find a home - Gothamist