Category Archives: Astronomy

Theyre holding a day of sky-related events 4-10 p.m. Saturday, May 7, in honor of National Astronomy Day, and itll be well worth your time to register. The observatory is north of Lake Maumelle in easternmost Perry County, about 35 from the I-430 and Highway 10 interchange. (Youll get more specific directions after you register.)

The details (including what to bring along and what NOT to bring along), and a registration link:

National Astronomy Day Solar and Lunar observing event River Ridge Observatory.

This special event is free, but attendance will be limited to 80 people. All ages welcome. A link to register is below, and you must register to attend. If you register and have a change of plans, please email info@caasastro.org.

Presentations and Activities:

4:00 6:00 Solar observing with h-alpha solar and Sunspotter scopes.4:00 6:00 Giant Bubbles & Stomp Rockets Observing Field4:00 6:00 Childrens Celestial Art Contest Deck4:00 8:00 Information Tables:2024 Solar Eclipse Display Darcy HowardArkansas Natural Sky Association tableUALR meteor collection4:15 4:25 Welcome to the RRO & Star Party Etiquette Amphitheater4:30 5:15 Novice Observer Program Classroom5:15 6:00 Saving the night sky for wildlife and humans Classroom6:00 7:00 Dinner, telescope show and tell, Q&A, & telescope help Observing Field7:00 7:25 Using binoculars for sky watching, star-hopping, and the celestial scavenger hunt Amphitheater7:30 7:45 Constellation tours Observing Field, Deck, and Parking Area7:45 10:00 Telescope observing, and celestial scavenger hunt

Guidelines and suggestions:This is not a dark-sky event as always on NAD a quarter moon will be up. Still, white flashlights, flashing shoes, and such are not allowed on the observing field and cell phones should be turned off. You can use a white flashlight to get to and from your vehicle as parking will be on the road. Otherwise, you probably dont need a flashlight unless you are doing the celestial scavenger hunt. If you think you might want a light on the Observing Field, bring a red flashlight or place red film (available in some arts and craft shops or auto parts stores) over a white light, or buy a small red key chain light at the event ($5 w/neck-lanyard).

Folding chairs, ground blankets, bug spray, and warmer than you think needed clothes might prove desirable. If you want to try your hand at the celestial scavenger hunt and have binoculars, bring them. There will be a few binoculars for loan, first come first served. Want help with setting up a telescope, bring it. If you register, please plan to attend the whole event. In any case, last entry is at 9:15. No drugs, alcohol, or pets, please.

Eats & Drinks

CAAS is not a Retail Food Establishment and you are welcome to bring your own food. However, grilled chili dogs, sausages, and fixings will be available. Suggested donation of $6 for adults, $4 for children appreciated. Snacks and drinks will be available for sale.

Okay, if you are ready to join in, registerhere.

Link:

National Astronomy Day celebration at River Ridge Observatory Saturday - Arkansas Times

SCITUATE Skyscrapers Inc., Rhode Islands amateur astronomy society, will be celebrating Astronomy Day at several places on Saturday, May 7.

At Roger Williams Parks Museum of Natural History, 1000 Elmwood Ave., Providence, from 12:30 to 3:30 p.m., members will have exhibits explaining varied astronomical subjects, such as Safely Observing the Sun, Introducing Astronomy, Exoplanets, the James Webb Space Telescope, and Light Pollution and its Effects. In addition, the Cormack Planetarium will have programs at 1 and 2 p.m. (reservations required).

Ladd Observatory, 210 Dolye Ave., Providence, will have safe solar observing on its lawn from 1 to 3 p.m.

Seagrave Memorial Observatory, 47 Peep Toad Road, invites the public to its monthly meeting at 7 p.m., featuring a talk by member Richard Lynch on his recent trip to Italy, where he visited the Vatican Observatory and different sites made famous by astronomer Galileo Galilei in the 1600s. Clear skies permitting, the organizations historic 8-inch Alvan Clark refracting telescope, plus its more modern reflecting telescopes, will be open for deep-sky observing.

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Celebrate Astronomy Day with Skyscrapers Saturday | The Observer | valleybreeze.com - Valley Breeze

WEST LAFAYETTE, Ind. A Purdue University physics and astronomy professor whose work is dedicated to environmental safety and enhancing renewable energy production has been elected to one of the nations highest science honors.

Laura Pyrak-Nolte, Distinguished Professor of Physics and Astronomy in the College of Science, has been elected to one of the nations oldest and most prestigious honorary societies, the American Academy of Arts and Sciences. Pyrak-Nolte, who is recognized as the worlds leading expert on the acoustic, mechanical and transport characteristics of porous and fractured media, is one of 261 members of the newest academy class. Her work in this field leads to innovation in the availability of fresh water to drink, the power of geothermal resources to heat and cool our homes, and aids the modern energy economy that relies on the injection and withdrawal of fluids through fracture networks in rock.

Her research has led to novel ways to reveal how seismic waves can be utilized to characterize fractured rock masses and how the fractured medium affects the propagation of seismic waves. She leads the Rock Physics Research Group that studies the physics of fractures in rock, detecting whether they slip or leak fluids into the environment. Understanding fractures is vitally important to a wide range of fields, including improving the safety and efficacy of geothermal energy and natural gas production, carbon sequestration and nuclear waste disposal.

We are enormously proud of ProfessorPyrak-Nolte and her scientific achievements, said Patrick J. Wolfe, the Frederick L. Hovde Deanof the College of Science. "This latest well-deserved recognition for her work in geophysics is absolutely emblematic of our efforts to elevate Purdue Science to ever-greater heights in research and scholarly impact."

Pyrak-Nolte also is an elected member of the National Academy of Engineering, a fellow in American Association for the Advancement of Science, and a fellow in the American Geophysical Union. These allocations recognize Pyrak-Noltes distinguished efforts toward advancing scientific applications.

She also holds courtesy appointments in both the Lyles School of Civil Engineering and the Department of Earth, Atmospheric, and Planetary Sciences at Purdue.

I am honored to have been elected to the American Academy of Arts and Sciences, and I want to thank Purdue, the College of Science, and the Department of Physics and Astronomy for their support during my career, Pyrak-Nolte said.

This distinction recognizes achievements of individuals in academia, the arts, business and public affairs. The 2022 class will be inducted at a ceremony in Cambridge, Massachusetts.

Those from Purdue previously elected to membership include:

Founded in 1780, the American Academy of Arts and Sciences is an independent research center that conducts multidisciplinary studies of complex and emerging problems. Current academy research focuses on science and technology, global security, social policy and American institutions, the humanities and culture, and education. Headquartered in Cambridge, Massachusetts, the academys work is advanced by its 4,600 elected members worldwide who are leaders in the academic disciplines, the arts, business and public affairs. Among its fellows are more than 250 Nobel Prize winners and more than 60 Pulitzer Prize winners.

About Purdue University

Purdue University is a top public research institution developing practical solutions to todays toughest challenges. Ranked in each of the last four years as one of the 10 Most Innovative universities in the United States by U.S. News & World Report, Purdue delivers world-changing research and out-of-this-world discovery. Committed to hands-on and online, real-world learning, Purdue offers a transformative education to all. Committed to affordability and accessibility, Purdue has frozen tuition and most fees at 2012-13 levels, enabling more students than ever to graduate debt-free. See how Purdue never stops in the persistent pursuit of the next giant leap athttps://stories.purdue.edu.

Writers: Bella Vina and Cheryl Pierce

Media contact: Amy Patterson Neubert, apatterson@purdue.edu

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Purdue physics and astronomy professor named to American Academy of Arts and Sciences - Purdue University

Associate Professor Allison Jaynes has been awarded$543,000 from the University of Colorado, Boulder to build and deliver an energetic particle instrument for a rocket mission, COUSIN: A Study of Small-Scale Auroral Region Energy Deposition.

COUSIN is a sounding rocket investigation designed to address fundamental open questions of the auroral electrical current system, focusing on small-scale structure and energetics and their impact on the thermosphere,according to Principal Investigator David Malaspina, assistant professor at the University of Colorado, Boulder.The mission is expected to be flown in February 2024 from Esrange Space Center in Sweden and is part of the full European SYSTER sounding rocket mission.

Jaynes is the Principal Investigator for Proton eLectron Advanced Sensor for M-I Coupling (PLASMIC), an energetic particle detector that will measure electrons coming down into Earth's atmosphere from space. It is based on a solid-state silicon detector design to measure energies from 10's keV to several MeV. These energies are important for understanding the total energy budget that is dumped into our atmosphere from space particles.

Malaspina said the COUSIN mission seeks to address two scientific questions:

By addressing these questions, COUSIN will elucidate fundamental electrodynamics processes at scale sizes that have not been comprehensively examined, yet are suspected to play a large role in coupling the Earths solar-wind driven magnetosphere with its charged particle ionosphere and neutral atmosphere, Malaspina said.

PLASMIC is among fiveCOUSIN instruments that are uniquely capable of achieving significant scientific progress by making the first coordinated measurements at small scales (< 2 km) of plasma, precipitation, and neutral parameters required to determine thermospheric energy deposition and response at the altitudes where it maximizes.

Seehttps://malaspinaspacephysics.com/missions-and-instruments/for more information.

Banner image:(a) PLASMIC detector stack flight model (b) PLASMIC daughterboard. Credit: Allison Jaynes

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Jaynes Awarded $543,000 To Build Auroral Particle Detector | Physics and Astronomy - The University of Iowa - The University of Iowa

Have you heard that on May 6, 2022 this Friday! an asteroid the size of the Great Pyramid in Giza may hit Earth?

You might have if you listen to conspiracy-laden YouTube videos and news sites online that make breathless claims without being overly burdened with a predilection for accuracy.

To be clear: No, an asteroid the size of an Egyptian pyramid wont hit the Earth on Friday. First of all, its not anywhere near that big, and second, its likely to miss us by tens of million kilometers.

Heres the deal. On May 4, 2009 the Catalina Sky Surveys telescope in Arizona designed to scan large areas of the sky every night to look for near-Earth asteroids and comets found an asteroid in its observations, now called 2009 JF1.

Asteroids appear as a dot moving from frame to frame as images are taken over the course of a night, and using its position versus time its possible to calculate the shape of its orbit. The initial calculations showed that 2009 JF1s orbit came very close to Earth, within a mere 200,000 kilometers or so, less than half the distance to the Moon. Thats a cause for concern though not necessarily alarm; its difficult to get a very accurate orbital calculation over so short a time frame:

At the time, 2009 JF1 was very faint and was only able to be tracked for roughly 30 hours, not nearly enough to get a good grip on where it would be in the future. Still, extrapolating its motion showed that on May 6, 2022 there was a 1 in 4,000 chance it would hit Earth.

Think of it this way: Thats a 99.975% chance it would miss. Out of caution, as usual, astronomers knew the prediction was extremely rough but kept this rock in mind.

Not that they were particularly worried. Given the asteroids distance and brightness in those 2009 observations, they calculated it was small, probably 10 meters in size. Thats smaller than the asteroid that broke up over Russia in 2013, so clearly not anything that will cause an Earth-shattering kaboom.

Still, this was enough that the European Space Agencys Near-Earth Object Coordination Center which keeps track of such objects put in on their risk list, and the nominal odds were high enough to keep it pretty high up on that list.

That was 13 years ago, and progress marches on. Over the years astronomers have developed software to better analyze asteroid orbits. Also, missions like Gaia have hugely improved our measurements of star positions, which are used as benchmarks for the asteroid orbit calculations. The original observational data were archived, so recently astronomers reanalyzed them using better software and stellar positions.

And guess what? The chance of an impact dropped precipitously. With the new measurements the impact risk went from 1 in 4,000 to 1 in 170,000. In other words, a 99.9994% chance it will miss.

Ill take that action. And because of this new work, the NEOCC took 2009 JF1 off its priority list.

The real situation is that the nominal, or statistically most likely, miss distance will be about 24 million kilometers 15 million km or so. The date of closest approach will actually be May 15, plus/minus a day.

So, were safe. OK? OK.

Now, if you search for the asteroid online youll find a ton of garbage sites about it. I see many saying NASA announced it will hit on May 6, but the weird thing is they never link to that claim. Funny, that. Another NASA says phrase that comes up a lot is, Some asteroids and comets follow orbital paths that take them much closer to the Sun and therefore Earth than usual. However, I can find nothing online from NASA saying that. Mostly these nonsense sites just steal from each other; I have found more credible sites with this statement but nothing like this as a direct quotation from NASA. And a few sites use this quote talking about a completely different asteroid. That doesnt exactly inspire trust.

And a lot of sites are saying 2009 JF1 is huge, 100+ meters across, but again that was never true, even from the very first observations. It was known from day one to be small. Thats why it was never classified as a Potentially Hazardous Object those need to get within 7.5 million kilometers of Earth and be at least 140 meters wide. This one can get closer, but is too small to be a real threat.

I say this every time I hear about these claims of an asteroid impact: Ask yourself about the site or person making this claim. Are they an astronomer? Does it really come from NASA? Or ESA, or any official astronomical organization?

Remember, too: If I hear of an actual asteroidal threat, you can bet your last penny Ill be screaming about it here on the blog and on every social media platform I have access to. So if you dont hear about it from me, youre probably OK.

And stop going to YouTube channels with names like NASALies69420SheepleFlatEarth$NFT$ for your science info. Or anything. I will take that as a personal favor.

Excerpt from:

Bad Astronomy | Asteroid 2009 JF1 will not hit Earth on May 6 2022 | SYFY WIRE - Syfy

by Nicholas Stewart, Iowa's News Now

NASA selected the University of Iowa as one of three recipients of a $250,000 award for a study to help improve space weather forecasting.

Over the next four months, a team led by Assistant Professor David Miles at UI will develop and perfect plans for an instrument called a magnetometer. This instrument will better help understand how storms from the sun can affect vulnerable infrastructure on earth like the electrical grid.

If selected to move forward, this will be a first step to better forecast space weather events, similar to the way weather satellites were first launched in the 1960s to better forecast hurricanes, flood events and tornadoes on earth.

Eventually, it hopes to enable a space weather forecast, but to get there we have to understand small things, medium things, and whole earth things, Miles said. To understand the underlying mechanics and the underlying physics, so we can hopefully forecast it.

If NASA selects Iowas instrument, the magnetometer will be included in a fleet of satellites which is currently expected to launch as early as September 2027.

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NASA awards UI $250,000 for space weather research | Physics and Astronomy - The University of Iowa - The University of Iowa

For over 70 years, astronomers have been scanning for radio or optical signals from other civilizations in the search for extraterrestrial intelligence (SETI). Most scientists are confident that life exists on many of the 300 million potentially habitable worlds in the Milky Way Galaxy. They also think there is a decent chance some life forms have developed intelligence and technology. But no signals from another civilization have ever been detected, a mystery that is called The Great Silence. While SETI has long been a part of mainstream science, messaging extraterrestrial intelligence (METI) has been less common.

Astronomers hope to send a message toward the center of our Milky Way Galaxy. Image credit: Andriy Sydorenko.

In the coming months, two teams of astronomers are going to send messages into space in an attempt to communicate with any intelligent aliens who may be out there listening.

These efforts are like building a big bonfire in the woods and hoping someone finds you. But some people question whether it is wise to do this at all.

History of METI

Early attempts to contact life off Earth were quixotic messages in a bottle.

In 1972, NASA launched the Pioneer 10 spacecraft toward Jupiter carrying a plaque with a line drawing of a man and a woman and symbols to show where the craft originated.

In 1977, NASA followed this up with the famous Golden Record attached to the Voyager 1 spacecraft.

These spacecraft as well as their twins, Pioneer 11 and Voyager 2 have now all left the Solar System.

But in the immensity of space, the odds that these or any other physical objects will be found are fantastically minuscule.

Electromagnetic radiation is a much more effective beacon.

Astronomers beamed the first radio message designed for alien ears from the Arecibo Observatory in Puerto Rico in 1974.

The series of 1s and 0s was designed to convey simple information about humanity and biology and was sent toward the globular cluster Messier 13 (M13). Since M13 is 25,000 light-years away, you shouldnt hold your breath for a reply.

In addition to these purposeful attempts at sending a message to aliens, wayward signals from television and radio broadcasts have been leaking into space for nearly a century.

This ever-expanding bubble of earthly babble has already reached millions of stars.

But there is a big difference between a focused blast of radio waves from a giant telescope and diffuse leakage the weak signal from a show like I Love Lucy fades below the hum of radiation left over from the Big Bang soon after it leaves the Solar System.

Sending New Messages

Nearly half a century after the Arecibo message, two international teams of astronomers are planning new attempts at alien communication.

One is using a giant new radio telescope, and the other is choosing a compelling new target.

One of these new messages will be sent from the worlds largest radio telescope, in China, sometime in 2023.

The telescope, with a 500-m (1,640-foot) diameter, will beam a series of radio pulses over a broad swath of sky. These on-off pulses are like the 1s and 0s of digital information.

The message is called The Beacon in the Galaxy and includes prime numbers and mathematical operators, the biochemistry of life, human forms, the Earths location and a time stamp.

The team is sending the message toward a group of millions of stars near the center of the Milky Way Galaxy, about 10,000 to 20,000 light-years from Earth.

While this maximizes the pool of potential aliens, it means it will be tens of thousands of years before Earth may get a reply.

The other attempt is targeting only a single star, but with the potential for a much quicker reply.

On October 4, 2022, a team from the Goonhilly Satellite Earth Station in England will beam a message toward the star TRAPPIST-1.

This star has seven planets, three of which are Earth-like worlds in the so-called Goldilocks zone meaning they could be home to liquid and potentially life, too.

TRAPPIST-1 is just 39 light-years away, so it could take as few as 78 years for intelligent life to receive the message and Earth to get the reply.

Ethical Questions

The prospect of alien contact is ripe with ethical questions, and METI is no exception.

The first is: Who speaks for Earth? In the absence of any international consultation with the public, decisions about what message to send and where to send it are in the hands of a small group of interested scientists.

But there is also a much deeper question. If you are lost in the woods, getting found is obviously a good thing.

When it comes to whether humanity should be broadcasting a message to aliens, the answer is much less clear-cut.

Before he died, iconic physicist Stephen Hawking was outspoken about the danger of contacting aliens with superior technology.

He argued that they could be malign and if given Earths location, might destroy humanity.

Others see no extra risk, since a truly advanced civilization would already know of our existence. And there is interest.

Billionaire Yuri Milner has offered $1 million for the best design of a new message and an effective way to transmit it.

To date, no international regulations govern METI, so the experiments will continue, despite concerns.

For now, intelligent aliens remain in the realm of science fiction.

Books like The Three-Body Problem by Cixin Liu offer somber and thought-provoking perspectives on what the success of METI efforts might look like.

It doesnt end well for humanity in the books. If humans ever do make contact in real life, I hope the aliens come in peace.

_____

Author: Chris Impey, distinguished professor of astronomy at the University of Arizona.

This article was originally published on The Conversation.

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Two Teams of Astronomers Want to Broadcast Earth's Location for Intelligent Extraterrestrials - Sci-News.com

The mystery of how giant stars spend their last moments before exploding in radiant death just got a little closer to being solved, in part by researchers who challenged the idea that implied models are sufficient for studying dying stars.

In a paper published Tuesday in The Astrophysical Journal, astronomers at the University of Texas, Austin describe a new model for what they think happens when some of the biggest stars in the cosmos explode as supernovae at the end of their lives, before turning into neutron stars or black holes.

When stars eight times as massive as the Sun or larger burn through their hydrogen fuel, they begin fusing ever more heavy elements such as oxygen, silicon, and eventually iron. At that point, unable to sustain the thermonuclear reactions at their core that push against their own massive gravity, they collapse in on themselves and explode in a supernova.

Despite burning through most of their hydrogen, some supermassive stars retain an outer layer of hydrogen gas up until the time they explode. But a certain type of supernovae, Type IB, involves stars that have lost this outer layer of hydrogen.

Scientists like University of Texas, Austin professor of astronomy Craig Wheeler would like to know how those stars lose that hydrogen.

What were trying to understand is what makes these massive stars blow up, he said. Understanding what mass ejection they do shortly before they explode is one piece of that, in some sense, even yet bigger story of how the massive stars evolve and die.

In 2014, a star 40 million light years away in the spiral galaxy NGC 7331 went supernova, and observers quickly classified it as a Type 1B, as there was no evidence of hydrogen in the light coming from the explosion. But as Wheeler and his colleagues watched the light from SN 2014C over the coming months and years, they were puzzled they began seeing evidence of hydrogen where there had been none.

The supernova SN 2014C in the distant NGC 7331 galaxy as seen in visible and X-ray light

(Nasa)

If you look at a supernova that when it blows up has no hydrogen in it. And then a little bit later, months, a year, even a decade later, starts showing evidence for hydrogen emission, that suggests that it used to have hydrogen it blew it off into the surrounding medium, Dr Wheeler said. Then the supernova explodes and collides with that previously rejected hydrogen.

What Dr Wheeler and his colleagues suggest in the paper is that SN 2014C took place in a binary star system and that the companion of the star that exploded helped draw off the outer layer of hydrogen from the dying star before it exploded. The stellar winds of both stars then pushed the hydrogen out into the space around the pair in a common envelope.

But thats not a new idea. What Dr Wheeler believes is important is the shape of the common envelope his findings show it has to be a disk.

Theres an old joke that all physicists first assume that cows are spherically symmetric, Dr Wheeler said, the point being that physicists often make simplifying assumptions about phenomena to get started on a problem. In the case of SN 2014C, he said, most of the models assumed that the common envelope around the two stars was roughly spherical, and that the supernova blast expanded spherically.

But when Dr Wheeler and his team crunched all the numbers, they found contradictions in the data so long as they tried to put them into a symmetrical, spherical model.

It had to be asymmetric in some way, and so weve argued that [the hydrogen is] coming off in a disk, and that helps us to put all of the data together in a coherent picture, he said. Not just that it might be asymmetric, but it absolutely damn well must be asymmetric, is one of the main messages of our paper.

Material orbiting massive objects as a disk is not unusual in astronomy, Dr Wheeler points out. The matter whirling around black holes before slipping inside is compressed into a disk, planets form out of disks of dust around stars, and galaxies themselves are, to an extent, disk-like.

But many physicists, Dr Wheeler said, have used spherical assumptions when using computers to model Type Ib supernovae to calculate the simplest thing they could get away with that explored what they were looking at.

Were going to have to do a pause on that, he added.

And while questions of how astronomers model supernovae might seem arcane to lay readers, Dr Wheeler points out that they are pieces in a much larger puzzle that covers almost the entire cosmos. Supernovae are what generate the heavier elements like iron, silicon, and carbon necessary for Earth-like planets and Earth-like life, while the neutron stars and black holes these massive explosions result in tug and twist at the fabric of reality itself.

Better understanding how to model supernovae will help scientists better understand the universe, and Dr Wheeler is arguing that this asymmetric model may apply to many supernovae across the universe, and not just SN 2014C. Hes given it a lot of thought, but he readily admits he could be wrong, and is looking forward to the scientific communitys response to the paper.

I think that our colleagues are going to have to sit back and, you know, rub their chins and think about this and assimilate that into their picture, Dr Wheeler said. Theres a meeting in Munich next fall that Im not sure Im going to be able to go to, but theyll all be there and it would be great fun to have this conversation.

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Astronomers reveal new clue as to why giant stars explode - The Independent

I see that Jupiter is aligned with Mars (C8) at the moment, says Geoff Gilligan of Coogee. Could this be the dawning of the Age of Aquarius? Should I get out my old flared jeans and tie-dyed T-singlets? Richard Stewart of Pearl Beach wonders if were headed for a span where peace will guide the planet and love will steer the stars and asks if anyone recalls the interval of the musical where the whole cast was naked. Ah, memory.

Colin Taylor-Evans of Lane Cove has some advice for 10-year-old Rachael, mentioned last month as the future beneficiary of a 1985 Toyota Starlet, currently in the care of her grandfather, John Ure (C8). Rachael will turn 13 the year her car-in-waiting turns 30. I suggest she applies for associate membership of her local enthusiast car club, catering to the manual drivers of Mount Hutton. Her 30-year-old Toyota will then be eligible for Conditional Historic Vehicle Registration, greatly reduced rego fees and insurance, though limited to 60 days per year of usage. Dont want to wear out that clutch!

Currently holidaying in Tasmania, I was surprised that so many Tasmanians mourn their dead grass to the point where they have established many lawn cemeteries, notes Peter Miniutti of Ashbury.

Sorry, Norma Brown (C8) but the kookaburra aint solitary. Mark Fuller of Armidale is lucky enough to have a large family of kookaburras on my small (15 acres) property. I have witnessed seven together, which is good as they are great for keeping snakes down. Corinne Johnston of Gymea Bay adds: No one has told our group of three kookaburras that they are solitary, nor the riot of about 15-20 circling our huge ironbark tree last week, like something Hitchcock designed.

Regarding the collective noun aspect, Patrick McMahon of Paddington asks: Remember Monty Python inventing a flange as the group name for gorillas. People believed it and I think its still used.

Margaret Grove of Abbotsford writes: Michael Morton-Evans (C8), the name Hyphen still has two syllables. While not entirely correct, Dash would be shorter. Indeed, Charles Davies-Scourfield of Culburra Beach says: My prep school name was Dash. My grandfather was triple barrelled with perhaps the longest name, Saunders-Davies-Scourfield, but wisely reduced it.

My first policy as a Column 8 candidate (C8) would be to immediately disendorse anyone who claimed John Hopkins University as their alma mater, promises Kevin Harris of Beecroft.

Column8@smh.com.au

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Hair-raising moments in astronomy - Sydney Morning Herald

One of the most pernicious mysteries in astronomy right now is easy to state but proving ridiculously hard to answer: How do supermassive black holes form?

These are enormous black holes, called supermassive black holes, some with millions or billions of times the mass of the Sun, and it looks like every decently sized galaxy in the Universe has one in its core. The thing is, we see them in galaxies at the very edge of the observable Universe, which means we see these galaxies when they were less than a billion years old. That in turn means these black holes form fast, in fact too fast according to most models. It's really hard to feed them rapidly enough to get them so big so soon after the Universe itself as born.

There's been a lot of work on this topic, and one of the more workable ideas is that some black holes are born kinda sorta massive, maybe 100,000 times the Sun's mass, and then they grow from there. These are called seed black holes. They may form in different ways; one avenue of active research is seeing if they can form directly from the collapse of gas clouds as a galaxy itself forms.

Another way is being investigated as well. Many big galaxies have large clusters of stars in their cores, called nuclear star clusters. These can be truly enormous clusters containing millions of stars, and range in total mass of a hundred thousand to tens of millions of times the Sun's mass, yet they're only a couple of dozen light years across. So they're not just massive, they're dense. Stars are packed together way more tightly than they are, say, near the Sun. The nearest star system to us is over four light years away. In a nuclear star cluster there would be tens of thousands of stars that close!

The star clusters themselves may form in the centers of galaxies, or they may be created when globular clusters, themselves dense balls of stars, fall to the centers of galaxies. Either way, theoretical models that is, looking at the physics of gravity and stars and black holes, and seeing how they all interact predict that nuclear star clusters can make and grow seed black holes pretty rapidly.

When massive stars die, they explode, blowing away their outer layers, while their cores collapse to form black holes. If the cluster is massive enough an important criterion these will fall to the center of the cluster, merge, and form bigger black holes. As stars pass close to this new black hole they can get torn apart and eaten about half the star's mass gets ejected and half falls into the black hole or they can fall toward the black hole, get captured by it through complicated gravitational processes, and get eaten more efficiently.

Either way, stars get et. The black hole grows.

The mass of the cluster is critical here. The math predicts that above a certain mass the cluster inevitably makes a black hole. It's hard to measure the mass of a cluster directly, but there's an indirect way: The more massive a cluster the bigger the spread of star speeds inside the cluster ones at the outer parts move slowly, and ones toward the center move pretty rapidly what astronomers call the velocity dispersion. This is a measurable quantity from observations, and the critical velocity dispersion in this case is about 40 kilometers per second.

So a team of astronomers looked at 108 big nearby galaxies with nuclear star clusters that had both Hubble Space Telescope observations to get their velocity dispersions, and Chandra X-ray Observatory observations to look for black holes [link to paper]. As gas piles up outside the black hole it heats up and emits X-rays, and that can be used to see if a black hole is there.

Long story short the observations and analysis are a bit tricky they found that galaxies with clusters above that 40 km/sec threshold have black holes in them at twice the rate of clusters with a lower velocity dispersion, and therefore a lower mass.

This is in line with what those theoretical models predict, which is heartening. That means this is likely a viable way to make seed black holes!

Also, this method of making big black holes is independent of distance. We do see enormous black holes forming when the Universe is young, so it's possible that's tied with how galaxies themselves form. But it's also possible some black holes grow more slowly, even after the galaxy itself has matured and all that available gas gets used up to make stars. That means forming black holes directly from collapsing gas is much, much harder as the Universe ages.

The beauty of forming them in nuclear star clusters, though, is that this could work when the Universe was young or much later as well. It could still be working today; in fact these nearby galaxies with nuclear star clusters are still adding mass to their black holes right now.

So this all fits together, which is neat. More observations would help; getting better statistics is always nice, and it would be beneficial to be able to measure just how efficient it is for these black holes to tidally capture stars.

But the good news is that this is a promising avenue to travel down; nuclear star clusters do seem to be black hole nurseries, and that gives us another way to make these monsters in galactic middles.

Our home Milky Way galaxy has a supermassive black hole in its core, called Sgr A*, and we don't really know how it formed. But we do know a lot of galactic characteristics depend on that black hole, on how they formed and affected each other, so figuring out how they are born and grow is key to figuring out why galaxies are the way they are. Including our own.

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How to create a massive black hole: Let it feed on a very dense star cluster - Syfy