Category Archives: Astronomy

My Journey in Becoming a Hand and Upper Extremity Surgeon

Bilal Mahmood, M.D. (U'08)

Assistant Professor, Department of Orthopaedics, University of Rochester Medical Center

At Union, I majored in Mathematics and Physics. I've always considered the purity of mathematics unrivaled in all the sciences, with physics its closest sibling. The physics department remained home-base, thanks in large part to the welcoming nature of Colleen Palleschi, the department's administrative assistant. I was privileged to do research with Professors Koopmann and Newman, and truly enjoyed my time in the department. I decided to pursue medicine while a second year. It wasn't until the beginning of fourth year in medical school that I settled on Orthopaedic Surgery. Once in residency, it did not take long to focus in on Hand Surgery as a subspecialty. Formalized in World War II, Hand Surgery developed as a distinct subspecialty because of the mixture of orthopaedics, plastics, general surgery, neurosurgery, vascular surgery, micro surgery, and even psychiatry involved. A hand surgeon is responsible for the musculoskeletal system, soft tissue, vascular system, and peripheral nerves. The idea of being fully responsible for one part of the body and providing complete care was my reason for choosing Hand Surgery. In this talk, I will share my journey in becoming a hand surgeon. I will show my day to day life, and show common as well as interesting cases in Hand and Upper Extremity Surgery.

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Department of Physics and Astronomy and the Health Professions Program Joint Colloquium - My Journey in Becoming a Hand and Upper Extremity Surgeon,...

Vera Rubin, a young astronomer at the Carnegie Institution in Washington, was on the run in the 1970s when she overturned the universe.

Seeking refuge from the controversies and ego-bashing of cosmology, she decided to immerse herself in the pearly swirlings of spiral galaxies, only to find that there was more to them than she and almost everybody else had thought.

For millenniums, humans had presumed that when we gaze out at the universe, what we see is a fair representation of reality. Dr. Rubin, with her colleague Kent Ford, discovered that was not true. The universe all those galaxies and the vast spaces between was awash with dark matter, an invisible something with sufficient gravity to mold the large scale structures of the universe.

Esteemed astronomers dismissed her findings at first. But half a century later, the still futile quest to identify this dark matter is a burning question for both particle physics and astronomy. Its a pursuit that stretches from underground particle colliders to orbiting telescopes, with all manner of ground-based observatories in between.

Last week the National Science Foundation announced that the newest observatory joining this cause will be named the Vera C. Rubin Observatory. The name replaces the mouthful by which the project was previously known: the Large Synoptic Survey Telescope, or L.S.S.T.

The observatory, jointly financed by the N.S.F. and the Department of Energy, under construction on a mountain called Cerro Pachon, in Chile, will begin operating in 2022. By recording images of the entire sky every few days, it will produce a time-lapse movie of the universe.

It is the first national observatory to have been named for a woman, the announcement said. Named after an astronomer who provided important evidence of the existence of dark matter, wrote France Crdova, the Foundations outgoing director, the NSF Vera C. Rubin Observatory seems destined to make science history with its extraordinary capabilities that will come to bear in the next few years.

The Rubin Observatory joins a handful of smaller astronomical facilities that have been named for women. The Maria Mitchell Observatories in Nantucket, Mass., is named after the first American woman to discover a comet. The Swope telescope, at Carnegies Las Campanas Observatory in Chile, is named after Henrietta Swope, who worked at the Harvard College Observatory in the early 20th century. She used a relationship between the luminosities and periodicities of variable stars to measure distances to galaxies.

And finally there is the new Annie Maunder Astrographic Telescope at the venerable Royal Greenwich Observatory, just outside London. It is named after Annie Maunder, who with her husband Walter made pioneering observations of the sun and solar cycle of sunspots in the late 1800s.

Heros of science, all of them.

In a field known for grandiloquent statements and frightening intellectual ambitions, Dr. Rubin was known for simple statements about how stupid we are. In an interview in 2000 posted on the American Museum of Natural History website, Dr. Rubin said:

In a spiral galaxy, the ratio of dark-to-light matter is about a factor of 10. Thats probably a good number for the ratio of our ignorance to knowledge. Were out of kindergarten, but only in about third grade.

Once upon a time cosmologists thought there might be enough dark matter in the universe for its gravity to stop the expansion of the cosmos and pull everything back together in a Big Crunch. Then astronomers discovered an even more exotic feature of the universe, now called dark energy, which is pushing the galaxies apart and speeding up the cosmic expansion.

These discoveries have transformed cosmology still further, into a kind of Marvel Comics super-struggle between invisible, titanic forces. One, dark matter, pulls everything together toward its final doom; the other, dark energy, pushes everything apart toward the ultimate dispersal, some times termed the Big Rip. The rest of us, the terrified populace looking up at this cosmic war, are bystanders, made of atoms, which are definitely a minority population of the universe. Which force will ultimately prevail? Which side should we root for?

Until recently the money was on dark energy and eventual dissolution of the cosmos. But lately cracks have appeared in the data, suggesting that additional forces may be at work beneath the surface of our present knowledge.

The discoverers of dark energy won the Nobel Prize in 2011. So far, dark matter has not been so honored. Dr. Rubin was perennially mentioned as a possible candidate for the prize. But she died in 2016, a poster child for the consistent failure lamented every October, when the prizes are announced of the Nobel committee to honor women, and of the general struggle of women in science to receive respect and opportunity.

Once, summoned to a meeting with an eminent astrophysicist, Dr. Rubin arrived to be told they would have to talk in the lobby, because women were not allowed upstairs in the offices. Years later, when she finally gained access to the 200-inch Palomar telescope in California, she found that there was no womens restroom there. So she taped an outline of a womens skirt over the image of the man on the door, turning it into a ladies room.

Now she has an observatory of her own. Among its main missions, the Rubin Observatory will investigate the cosmic push-pull between dark matter and dark energy, peeling back layers of the sky and of the past. Its data will chart how fast clusters of galaxies (drawn together by dark matter gravity) have grown over cosmic time, and how fast the spaces between these clusters (created by the push of dark energy) have grown as the universe has expanded.

The Rubin Observatory is expected to significantly advance what we know about dark matter and dark energy, Dr. Crdova said. So the Rubin name will have yet another way to inspire women and men eager to investigate. Dr. Crdova went on to praise Congress, which has steadfastly defended the foundations budget against White House cuts over the last few years.

Natalie Batalha, an astronomer at the University of California, Santa Cruz, who was one of the leaders of NASAs Kepler planet-hunting space mission, said, Its heartening and highly appropriate to see Vera Rubin honored in this way.

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Vera Rubin Gets a Telescope of Her Own - The New York Times

This looping animation depicts a southwesterly view one hour after sunset from 1331January 2020 at two-day intervals as seen from the heart of the UK. Dazzling magnitude-4.1 Venus passes just 4arcminutes (one-fifteenth of a degree) south of Neptune at 8pmGMT on Monday, 27January 2020, so both planets will fit in the same high-power telescope view from 6pmGMT until they set. Dont miss magnitude+4.2 naked-eye star Phi()Aquarii that lies within 0.9 east of magnitude+7.9 Neptune throughout the period. Note that the Moons apparent size on 27 and 29January is enlarged for clarity. AN animation by Ade Ashford.Even casual skywatchers cannot fail to notice brightest planet Venus currently hanging like a lantern above the southwest horizon at nautical dusk, which is presently about 6pmGMT for the centre of the British Isles. On 11January, Venus crossed the constellation border into Aquarius where it resides for the remainder of the month.

Neptune also currently lies in the constellation of Aquarius. Since the outermost planet shines at magnitude +7.9, its too faint to see with the naked eye, but it is a viable binocular target if you know where to look. Fortunately for skywatchers, Venus makes an increasingly convenient celestial signpost to Neptunes position as the gap between them closes throughout this month, culminating in a close conjunction on 27January 2020.Venus passes one-fifteenth of a degree south of Neptune at 8pmGMT at 27January 2020, but the pair will be very low in the UK sky. Observers in the British Isles are advised to look at 6pmGMT around the onset of nautical twilight when the two planets are about 19 high in the southwest. Their separation is slightly more than 7arcminutes at this time. In this simulated one-degree telescope field of view the magnification is 40-50. AN graphic by Ade Ashford.While there will no difficulty in identifying Venus in your telescope on the evening of 27January, Neptune may prove a little more difficult to see in the glare of its planetary sibling. Their difference amounts to a whopping 12 magnitudes, which is another way of saying that Venus is 63,000 times brighter than Neptune! If the outermost planet is lost in Venus dazzle, try to spot magnitude +4.2 star Phi()Aquarii in the same field of view shown above.

Venus narrowly misses PhiAquarii, passing just 56arcseconds south of the star at 05:20UT (5:20amGMT) on 28January. Sadly, this event will not be visible from Western Europe as the timing favours the North Pacific Ocean and the Hawaiian Islands. Neptune has its own close encounter with the star, passing just 2arcminutes north of PhiAquarii at 8:15pmGMT (20:15UT) on 10February 2020; observers in the UK can see the conjunction low in the west-southwest shortly after 6pmGMT that night.

Returning to this month, if you do succeed in viewing Venus and Neptune in the same telescope field of view, do bear in mind that their apparent proximity is merely a line of sight effect. On the evening of 27January, Venus lies a little more than 167million kilometres (or 1.117 astronomical units) from Earth, but outermost planet Neptune is a staggering 4,590million kilometres (or 30.683 astronomical units) distant.

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Venus dazzles at dusk and closes in on Neptune - Astronomy Now Online

Astronomers have detected five new planets, eight planet candidates, and confirmed three previously reported planets, around nine nearby M-dwarf (red dwarf) stars. Among the new planets, Gliese 180d and Gliese 229Ac are super-Earths located in the conservative habitable zones of their host stars; Gliese 433c is a cold super-Neptune candidate belonging to an unexplored population of Neptune-like planets.

An artists concept of the Gliese 180 planetary system, which is located 39 light-years away in the constellation of Eridanus. Image credit: Robin Dienel, Carnegie Institution for Science.

M-dwarfs are the most common stars in our Milky Way Galaxy and the primary class of stars known to host terrestrial planets.

The first terrestrial-mass planet was found around the M-dwarf Gliese 876.

Over the past decade M-dwarfs have been the principle targets for potentially habitable planets because their habitable zones are much closer to the star, and thus the potentially habitable planets have much shorter periods than those orbiting around Sun-like stars.

Many planets that orbit red dwarfs in the habitable zone are tidally locked, meaning that the period at which they spin around their axes is the same as the period at which they orbit their host star, said lead author Dr. Fabo Feng, an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science.

This is similar to how our Moon is tidally locked to Earth, meaning that we only ever see one side of it from here.

As a result, these exoplanets are a very cold permanent night on one side and very hot permanent day on the other not good for habitability.

Gliese 180d is the nearest temperate super-Earth to us that is not tidally locked to its star, which probably boosts its likelihood of being able to host and sustain life, he added.

Gliese 180d has a minimum mass of 7.49 times that of Earth and an orbital period of 106 days.

An artists concept of Gliese 229Ac, which is located 18.8 light-years away from Earth. It is the nearest temperate super-Earth to us that is in a system in which the host star has a brown dwarf companion. Image credit: Robin Dienel, Carnegie Institution for Science.

The other potentially habitable planet, Gliese 229Ac, is 7.93 times more massive than Earth. It orbits its parent star once every 122 days.

It is the nearest temperate super-Earth to us located in a system in which the host star has a brown dwarf companion.

The brown dwarf in this system, Gliese 229B, was one of the first brown dwarfs to be imaged.

It is not known if they can host exoplanets on their own, but this planetary system is a perfect case study for how exoplanets form and evolve in a star-brown dwarf binary system.

Our discovery adds to the list of planets that can potentially be directly imaged by the next generation of telescopes, Dr. Feng said.

Ultimately, we are working toward the goal of being able to determine if planets orbiting nearby stars host life.

The Neptune-mass planet Gliese 433c orbits its star at a distance at which surface water is likely to be frozen.

This planet is probably the first realistic candidate for direct imaging of cold Neptunes.

The team also detected three planets Gliese 422b, 433d, and 3082b and seven planet candidates Gliese 173b, 229Ab, 620b, 620c, 739b, 739c, and 911b.

We eventually want to build a map of all of the planets orbiting the nearest stars to our own Solar System, especially those that are potentially habitable, said co-author Dr. Jeff Crane, an astronomer at the Observatories of the Carnegie Institution for Science.

The findings appear in two papers in the Astrophysical Journal Supplement Series and the Astronomical Journal.

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Fabo Feng et al. 2020. Search for Nearby Earth Analogs. II. Detection of Five New Planets, Eight Planet Candidates, and Confirmation of Three Planets around Nine Nearby M Dwarfs. ApJS 246, 11; doi: 10.3847/1538-4365/ab5e7c

R.P. Butler et al. 2019. A Reanalysis of the UVES M Dwarf Planet Search Program. AJ 158, 251; doi: 10.3847/1538-3881/ab4905

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Astronomers Discover Five New Planets around Nearby Red Dwarfs | Astronomy - Sci-News.com

The Milky Way Galaxy contains billions of massive bright stars. These high-mass stars have masses ranging from tens to hundreds of times the mass of the Sun. Their existence plays a role which is paramount in astrophysics.

They end their lives as supernovae which dramatically influences their environment. Yet, how they form still remains a mystery. The best current theories predict an upper limit of only about eight times the mass of the Sun.

For these stars, this leads to a discrepancy between theory and observation, which resulted in several competing theories emerging to explain this. One prominent emerging theory proposes that high-mass stars achieve their final mass from bursts of episodic accretion onto the protostar to achieve its final mass.

This theory predicts short-lived, intense accretion bursts through which the protostar gains mass from its surrounding accretion-disk, followed by long periods of inactivity, possibly lasting hundreds to thousands of years. In January 2019, astronomers at Ibaraki University in Japan noticed that one such massive protostar, G358-MM1, showed signs of new activity indicative of a potential accretion burst.

In response, a collaboration of astronomers, the Maser Monitoring Organization (M2O), gathered several radio telescopes from Australia, New Zealand and South Africa (HartRAO) to form a telescope array capable of detecting small-scale emission stimulated by the heat of the accreting protostar.

The team, led by Dr Ross Burns (NAOJ and JIVE), compared multiple images over the span of a month which revealed a heat-wave of energy radiating outward from the location of G358-MM1. According to Dr Fanie van den Heever (HartRAO/SARAO, South Africa), the observations made by M2O is the first real-time evidence supporting the episodic accretion theory for high-mass star formation.

The global community of astronomers, astrophysicists and theoreticians are benefiting tremendously from the work done by M2O and the recent results obtained by this group. The paper was published in Nature Astronomy on Monday, 13 January 2020.

About the authors

The work is led by Dr Ross Burns in collaboration with other M2O members. Dr Burns is affiliated to the National Astronomical Observatory of Japan (NAOJ) and the Joint Institute for VLBI in Europe (JIVE).

The South African contributors include:

Credit to Katharina Immer, affiliated with JIVE, for the artists impression.

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Astronomers Detect Radiation Stimulated By Heatwave Of Intense Thermal Energy From A Massive New-born Star - Space in Africa

PUBLISHED: 06:30 15 January 2020

Charlie Connelly

(Original Caption) William Herschel (1738-1822), famous astronomer discovering the planet Uranus. He is assisted by his sister, Caroline Lucretia (1750-1848).

Archant

The great European astronomer Caroline Herschel discovered more than eight comets. CHARLIE CONNELLY adds to her star-borne legacy

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"At the heavens there is no getting, for the high roofs of the opposite houses." It was Boxing Day, 1822, when Caroline Herschel wrote these words in a letter to her nephew. She was 72 years old and had recently returned to her home town of Hannover after spending 50 years in England becoming one of the most important women in the history of astronomy. The discoverer of eight comets and a visionary cataloguer of the heavens, she had spent countless nights squinting through her one good eye into a telescope, sweeping the night's canopy for uncharted stars or the tell-tale twinkle of a new comet arcing through distant skies.

The death four months earlier of her brother William, founding president of the Royal Astronomical Society and since 1782 the King's Astronomer, with whom she had worked tirelessly for half a century, affected her deeply. It was grief that prompted the ill-judged decision to abandon England and return to the town where she had spent her formative years. Being away from the telescopes she had helped William to build was one thing, being crowded out of the night sky altogether by the tall Hannoverian buildings only increased her sense of ennui. She could barely see the moon.

Today there is a crater in the bed of the moon's Sea of Showers named for Caroline Herschel and the comet 35P/Herschel-Rigollet that passes within sight of the Earth every 155 years is also a tribute to her work. Back on Earth, in 1838 she became the first woman to receive the gold medal awarded by the Royal Astronomical Society - it would be 158 years before another woman received the award - and in 1846, her 96th year, she received a Gold Medal for Science from the King of Prussia, recognising her "valuable services to astronomy" rendered by "discoveries, observations, and laborious calculations".

Such honours still lay ahead of her as she cricked her neck at the window trying to see the stars that first Christmas without her brother in a land at once familiar yet strange: Hannover had changed almost beyond recognition in 50 years. Without her beloved brother, blocked from the stars and having already lived to a grand age, she must have felt as if her time was almost up but, as ever, Caroline Herschel wasn't done yet. She would live for another 26 years, still making a valuable scientific contribution through cataloguing and interpreting data even if she couldn't scan the heavens herself.

Such longevity was unthinkable when at the age of 10 she contracted typhus. Ill for months, sometimes dangerously so, the fact she only grew to be 4ft 3in was attributed to a disease that also deprived her of the sight in her left eye. For her mother Anna this meant only one thing: this daughter, her eighth child, would never marry and from an early age Caroline was prepared for life as a housemaid. Educating her would be a waste of time and money.

Her father Isaac disagreed. An oboist and conductor in the military, he recognised Caroline's intelligence and sought to encourage it. Long absences from a home where his wife ruled the roost frustrated attempts to give his daughter options, however. And, despite his teaching her whenever he had the chance, by the time she embarked on her twenties Caroline's only significant education was as a seamstress. When Isaac died in 1772 it appeared her course was set but William, 12 years her senior and a music teacher in Bath, had other ideas. He sensed his sister's melancholy from her letters and returned to Hannover determined she would accompany him to England where he would train her as a singer. It took several weeks to persuade Anna but on August 16, 1772, Caroline crossed the English Channel to a new life, aiming to "make the trial if by his instruction I might not become a useful singer for his winter concerts and oratorios".

William sought to coax the potential he'd recognised from a woman conditioned to believe she was practically worthless. Noting a nascent talent he coached her tirelessly and before long Caroline was a well-regarded soprano performing with him in the concert halls and salons of Bath and Bristol, taking leading roles in major works like Handel's Messiah.

Performing in public could not shift entirely the conditioning that had battered her self-esteem, however, and whenever other impresarios or conductors would approach her with offers of roles she would refuse them all. The thought of singing under anyone but her brother terrified her. Thus when William eventually abandoned music for his new passion of astronomy in the late 1770s it spelt the end of Caroline's singing career. He'd been spending spare evenings engrossed in books about the stars, repeating what he'd learned the previous night to his sister over breakfast. She absorbed everything. Before long he was enlisting Caroline's help in grinding and polishing lenses for the telescopes he was building and made Caroline his assistant, calling out his observations to her from his seat at the telescope to record in the copious notebooks she would fill for the rest of her life. Caroline was no mere stenographer, however. The data she was recording required advanced mathematical skills to interpret, something that came to her quite naturally.

By the turn of the 1780s, thanks in no small part to Caroline's labours with grinder and pen, William was able to abandon music altogether, discover the planet Uranus and be appointed to the post of King's Astronomer. Prestigious though the role was it had its drawbacks. Not only was it a reduced salary from his musical activities, the job necessitated a move closer to George III's royal residence at Windsor as the King's Astronomer was required to be available at the whim of the monarch. The Herschels moved first to Datchet and then to the observatory at Slough, and while Caroline was never a mainstay of Bath society the contrast between the lively, cultured city and the provincial backwater that became her home was marked.

She combatted loneliness and isolation by working tirelessly, sometimes at great physical cost. On New Year's Eve 1782 she was badly injured during a nocturnal observation, impaling her leg on an iron hook as William called for her to adjust the angle of his 40-foot telescope.

"[William] and the workmen were instantly with me but they could not lift me without leaving nearly two ounces of my flesh behind," she wrote later. "A workman's wife was called but was afraid to do anything and I was obliged to be my own surgeon by applying aquabusade and tying a kerchief about it for some days till Dr Lind, hearing of my accident, brought me ointment and lint, and told me how to use them."

The doctor told William later that "if a soldier had met with such a hurt he would have been entitled to six weeks' nursing in a hospital". Caroline Herschel was back recording observations within a couple of days. When William married a local widow in 1783 it could have exacerbated the dislocation Caroline felt in Berkshire. Instead she grasped her new intellectual freedom and gradually felt confident enough to begin making her own observations. "It was not till the last two months of the same year before I felt the least encouragement for spending the starlit nights on a grass-plot covered by dew or hoar frost without a human being near enough to be within call," she wrote of work she would come to describe as 'minding the stars'.

Within three years she had become the first woman to discover a comet and in 1796 became the first woman scientist to receive a salary when George III awarded her an annual stipend of 50. That year she commenced work on her other great achievement: reworking and updating John Flamsteed's 1725 British Catalogue of the stars he had observed from the Royal Observatory at Greenwich. It took nearly two years but Caroline Herschel's Catalogue of Stars not only corrected many errors but introduced 560 new heavenly bodies in a work that remains a valuable resource today.

Even when she returned to Hannover she kept up her cataloguing work, reorganising, correcting and indexing notebooks for her nephew and fellow astronomer John Herschel. Despite her clear gifts and achievements, the early intellectual and social stifling by her mother left Caroline's self-confidence in tatters for the rest of her life. When invited to the Royal Observatory at Greenwich by the Astronomer Royal Nevil Maskelyne during the 1790s she told him, "I am nothing. I have done nothing". She did add, however, that the invitation had "flattered my vanity", before adding revealingly that "among gentlemen this commodity is generally styled 'ambition'".

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The great life of astronomer Caroline Herschel, who catalogued the heavens - The New European

UCLA researchers have found that the black hole at the center of our galaxy may have a companion.

Many researchers currently believe that all stars in the Milky Way orbit a single supermassive black hole, known as Sagittarius A*. However, a recent UCLA-led study published in December discovered that a second black hole may exist alongside it.

Smadar Naoz, an associate professor of physics and astronomy at UCLA and the lead author of the paper, said most galaxies evolve by merging with other galaxies. As the majority of galaxies have a supermassive black hole at their centers, a galaxy could have multiple black holes at its center after merging with another galaxy, she added.

Its a cannibalism of galaxies, and if theres a supermassive black hole at the center of each galaxy, then just from gravity they will sink into the center, Naoz said.

Since researchers know theres a black hole in the center of the Milky Way, they expect that the black hole either had a younger sibling in the past or has one currently, Naoz said. She added that Sagittarius A* is unique because of its proximity to Earth.

Its a great lab to go and try to understand things that we have no chance of even detecting in other galaxies, Naoz said.

Clifford Will, a distinguished professor of physics at the University of Florida and a co-author of the study, said if there were a companion to Sagittarius A*, then its gravity would affect the orbits of the stars revolving around it, which is how researchers would find if there is a second black hole.

If there is a companion black hole to the big black hole that we know is there, its gravitational tug would perturb the orbits of the stars that we know are orbiting that black hole, Will said. Just the same way that the orbit of Jupiter perturbs the orbit of Uranus because Jupiter has its own gravitational attraction.

Tuan Do, a research scientist and deputy director at the Galactic Center Group at UCLA and a co-author of the study, said understanding this process is interesting because it is one of the ways black holes can grow. He added it is also interesting because when two black holes merge, they produce a lot of gravitational waves.

Will added that finding a companion black hole, or finding an absence of one, will lead to interesting insights about the Milky Ways past. If a second black hole is found, then the discovery could point out other processes that produce black holes in the center of existing galaxies. Additionally, the discovery could challenge current ideas of galaxy mergers, Will said.

Naoz said an absence of an additional black hole would mean that the Milky Way has not had any major mergers for about 10 million years. Sagittarius A* is only about 4 million solar masses, which means 4 million times the mass of the sun.

Our supermassive black hole is not one of the larger ones, Naoz said. So its not a bonafide billion. If we had any merger in the past, it was a minor merger. That means that smaller flimsy galaxies came to merge with us.

Naoz said they used measurements of the brightest star orbiting Sagittarius A*, called SO-2, to predict how the star should move going forward if there were a second black hole within its orbit. She added the environment at the galaxys center is very dense and the second black holes gravity should affect the orbits of these stars if it exists.

Between Earth (or) our solar system and the closest star, there is nothing, there are no more stars, Naoz said. But in the same distance, around the supermassive black hole, there are millions of stars. Thats how dense this place is.

Do added that SO-2s orbit around Sagittarius A* looks like an ellipse that slightly rotates every time the star completes one revolution. This motion is called precession, he said.

Naoz said precession resembles a flower pattern. If there was a second source of gravity affecting the orbits, she said, then this pattern would wobble slightly, creating a flower crown.

Using measurements of the orbit, Naoz said they could comfortably tell where the second black hole cannot be, as well as its range of mass.

We have a part of the parameter of space and mass and the separation (between) the supermassive black hole and its friend, (within which) its fair game, Naoz said. It can be there.

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Astronomers discover possibility of second black hole in Milky Way - Daily Bruin

Thousands of scientists from around the world are converging on Hawaii this week to unveil the latest discoveries about the universe at the so-called "Super Bowl of astronomy." If the event, the 235th meeting of the American Astronomical Society, had a stadium, it would be packed.

"This will be the biggest AAS meeting in history," AAS spokesperson Rick Feinberg told Space.com in an email.

More than 3,500 scientists are expected to attend the four-day conference in Honolulu, Hawaii, Feinberg said. The first press conferences and talks begin today (Jan. 5). They'll end on Wednesday (Jan. 8), with observatory tours and other presentations scheduled throughout the week.

NASA, as expected, will showcase its latest space findings at the conference, including the agency's recent exoplanet discoveries by the TESS space telescope and the Hubble Space Telescope, which celebrates its 30th anniversary in April.

"NASA researchers will present new findings on a wide range of astrophysics and other space science topics at the 235th Meeting of the American Astronomical Society, Saturday, Jan. 4, through Wednesday, Jan. 8, in Honolulu," NASA officials said in a statement. "Agency scientists and their colleagues who use NASA research capabilities also will present noteworthy findings during scientific sessions that are open to registered media."

The AAS and NASA will webcast press conferences from the conference daily from Sunday to Wednesday. There are two press conferences most days (there are three today) and they can be watched live on the AAS website here as well as on the NASA Live website here.

The briefings are scheduled for 10:15 a.m. HST (3:15 EST/2015 GMT) and 2:15 p.m. EST (7:15 p.m. EST/0015 GMT). The extra briefing on Sunday is at 12:45 p.m. HST (5:45 p.m. EST/2245 GMT).

You can find the list of the press conferences here, including what scientists will discuss in each session over the next four days.

The role of Hawaii in astronomy will take center stage at this year's AAS meeting.

"The main new feature of this meeting is our major effort to bring the astronomical community and the local community together as much as possible to discuss the future of astronomy in Hawaii," Feinberg said.

Hawaii has long been a focal point for astronomy. The Keck Observatory, which has the largest active optical telescopes on Earth, and other observatories sit atop the volcano Mauna Kea and an even larger telescope, the Thirty Meter Telescope, is planned to be built at the site.

But construction of the Thirty Meter Telescope (TMT) has been stalled due to ongoing protests by indigenous groups that consider Mauna Kea sacred. The demonstrations stepped up in 2019.

"TMT is committed to finding a peaceful way forward on Maunakea for all," the builders of the new telescope wrote in a Dec. 20 update.

"We are sensitive to the ongoing struggles of indigenous populations around the world, and we will continue to support conversations around TMT and the larger issues for which it has become a flashpoint," Gordon Squires, TMT VP for External Affairs, said in the statement. "We are participating in private conversations with community leaders, but these conversations will take time."

Email Tariq Malik attmalik@space.comor follow him@tariqjmalik. Follow us@Spacedotcom, Facebook and Instagram.

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The 2020 'Super Bowl of Astronomy' Kicks Off in Hawaii - Space.com

Beginnings of Cosmology

Humans have always held ideas about how the universe originated. But it wasnt until advances in the 20th century, including Albert Einsteins theories of relativity, that astronomers could really form educated ideas about how the universe formed.

Alexander Friedmann, a Russian physicist, was the first to realize that applying the rules of relativity across large scales described a universe that changed over time. With a mathematical approach, he showed the universe could have started small before expanding over enormous distances and, in some cases, eventually collapsing back in on itself.

Observations carried outby Lowell Observatorys V.M. Slipher and, later, Edwin Hubble, showed that the universe was in fact expanding. And this helped confirm these initial ideas of the Big Bang. Two years later, the Belgian physicist Georges Lematre published a paper describing how the expanding universe had started as a tiny, hot, dense speck, which he called the primeval atom. Ordained as a Catholic priest, Lematre reported the finding as a happy coincidence of cosmology and theology in an early draft of the paper, though the comment was removed for the final publication of the paper.

Two decades later, George Gamow would develop theories on the fallout of a hot-birthed universe namely, how it would create neutrons and protons and published a popular book on the subject. It even caught the eye of Pope Pius XII, who was taken by the parallels between the scripture of Genesis and the scientific theory.

Unlike the church, Einstein wasnt initially happy with the idea of a changing universe, preferring one invariable on large scales. British astronomer Fred Hoyle wasnt happy, either. Along with two other scientists, he developed a counter-theory the steady state model. The steady state model suggested that the universe had no beginning and had always been expanding. To explain why the universe looks identical in all directions, it proposed tiny traces of matter, too small to be experimentally measured, were continually being created.

This model initially garnered support of around half of the scientific community albeit one that was very small at the time and became the Big Bang theorys biggest rival.

This [debate between theories] was not in the mainstream of physics research, says David Kaiser, science historian and physics professor at MIT. Basically no one paid attention or very little attention, even among professional physicists and astronomers.

But as evidence started gathering, that would change.

Observations of distant ultra-bright galaxies in the 1950s suggested the universe was changing, and measurements of the helium content in the universe didnt match the steady state models predictions. In 1964, the monumental discovery of the cosmic microwave background radiation direct evidence of a young, hot universe would deal the final deathblow to the steady state model.

It really seems to suggest the universe had very different conditions in early times than today, Kaiser says. And that was just not what the steady state model suggests.

In an ironic twist, Hoyle used the term Big Bang in an attempt to dismiss the theory in a BBC interview. Though his own theory would be largely lost to history, the irreverent name would stick.

To his death, Hoyle would never submit to the Big Bang theory. A small subset of cosmologists still work on resurrecting a steady state model; but, on the whole, the community overwhelmingly supports the Big Bang theory.

There are a couple of other puzzles, so cosmologists don't think we're done, but theyre now kind of patching or filling in some holes to the original Big Bang models certainly not replacing it, Kaiser says.

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The Steady State: When astronomers tried to overthrow the Big Bang - Astronomy Magazine

Most massive meteorites struck Earth so long ago their craters have almost completely eroded, Sieh says. But this impact was unusual in that it was huge and recent enough that the site where it hit should be identifiable.But with rocks from the impact spread across the world, zeroing in on the location proved difficult.

The site eluded geochemists for decades, but Sieh decided to take a new approach and look at satellite imagery from parts of the world where the meteorite might have hit. In the Bolaven Plateau in southern Laos, he found an expanse of flat, shallow rock formed from hardened lava, just thick enough to obscure a crater of this size.

In-person excavations found the lava dated to around the same time as the impact, while surrounding sediments were older. Additional gravity measurements also hinted at a crater below. Altogether it's enough for Sieh to be confident he's finally located ancient ground zero.

With the help of Sieh and his teams find, researchers now have a slightly clearer sense of what must have happened after the asteroid hit. Roughly a mile and a quarter wide, the rock would have opened a hole larger than San Francisco in a span of seconds.

The rock's speed and force would have been enough to send pillow-sized boulders careening through the air at almost 1,500 feet per second. Sitting on the perimeter of the suspected impact site, these rocks are a tell-tale sign of a meteorite impact. It would not have been a healthy thing to be on the receiving end of that, Sieh says.

For now, Sieh wants to focus on some of the ashy material surrounding the meteor debris. The impact would have incinerated all plant and animal life within 300 miles of the impact site, and Sieh is curious how that kind of settling dust would impact all of us today. The odds of such an impact are extremely low, but still fascinate Sieh. "I've never worked on meteorites before, but I got sucked into this with my curiosity," he says.

As for drilling down through the rock to confirm that this is in fact the site? "I'm 98 percent convinced we found it, but Id be supportive of anyone who wanted to," he says.

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Crater found from asteroid that covered 10% of Earth's surface in deb - Astronomy Magazine