Universe Today

November 20, 2013December 23, 2015 by Tammy Plotner

Exploring Our Galaxy’s Ancient Brown Dwarfs

A brown dwarf from the thick-disk or halo is shown. Although astronomers observe these objects as they pass near to the solar system, they spend much of their time away from the busiest part of the Galaxy, and the Milky Way's disk can be seen in the background. Credit: John Pinfield

As the name implies, a brown dwarf is small… only about 7% the size of the Sun. As far as stellar senior citizens go, they’re cool. Zipping along through space at speeds of 100 to 200 kilometers per second, they may have formed back when our galaxy was young – perhaps 10 billion years ago. Now a team of astronomers headed by Dr. David Pinfield at the University of Hertfordshire has identified a pair of the oldest brown dwarfs known… a set of orbs which could be the harbinger of a huge amount of new, unseen objects.

Although we sometimes refer to them as stars, brown dwarfs are in a class of their own. Because they didn’t ignite in nuclear fusion, they don’t generate internal heat like an ordinary star. After they are formed, they continue to cool and fade as time passes. This process makes them very difficult to observe and the discovery of two very old brown dwarfs, with temperatures of 250-600 C is cause for astronomical excitement.

Just how did Pinfield’s team pick such tiny objects out of the vastness of space? The discovery was facilitated thanks to a survey made by the Wide-field Infrared Survey Explorer (WISE), a NASA observatory that scanned the mid-infrared sky from orbit in 2010 and 2011. The ancient objects are cataloged as WISE 0013+0634 and WISE 0833+0052, and they are located in the constellations of Pisces and Hydra. Because they are so elusive, they were also confirmed by large ground-based telescopes (Magellan, Gemini, VISTA and UKIRT).

However, identifying the pair wasn’t easy. Seeing through the eyes of infrared reveals a crowded space – one populated with reddened stars, distant background galaxies and pockets of nebulous gas and dust. Picking out such a small character from a stellar cast would be like finding one tiny pearl in the vastness of an ocean. But Pinfield’s researchers employed a new method which utilizes WISE’s capabilities. As it scanned the sky over and over again, it revealed the cool, brown dwarfs – picking up the faint signature that other searches had missed.

These two particular brown dwarfs are different from the other slow movers of their type. By studying their spectra, the astronomers have identified atmospheres almost entirely comprised of hydrogen. This sets them apart from younger stars which have an abundance of heavier elements. Does being lighter make them speedier? According to Pinfield, “Unlike in other walks of life, the galaxy’s oldest members move much faster than its younger population.”

Stars near to Sun are considered the “local volume” and are created with three overlapping populations – the thin disk, the thick disk and the halo. Each of these layers has a certain amount of age associated with it: the oldest being the thickest and its member stars move up and down at a higher rate of speed. The halo contains both disks, along with the initial materials which formed the very first stars. Thin disk objects abound in the local volume and account for about 97% of the local stars, while thick disk and halo objects are a meager 3%. Chances are, brown dwarfs belong to that smaller percentage which explains why these fast-moving thick-disk/halo objects are only now being revealed.

Just how many may await discovery? Scientists surmise there may be as many as 70 billion brown dwarfs in the galaxy’s thin disk, and the thick disk and halo take up significantly larger galactic volumes. Even at a tiny 3%, this means there could be an army of ancient brown dwarfs in the galaxy. “These two brown dwarfs may be the tip of an iceberg and are an intriguing piece of astronomical archaeology,” said Pinfield. “We have only been able to find these objects by searching for the faintest and coolest things possible with WISE. And by finding more of them we will gain insight into the earliest epoch of the history of the galaxy.”

Original Story Source: Royal Astronomical Society News Release. For further study: “A deep WISE search for very late type objects and the discovery of two halo/thick-disk T dwarfs: WISE 0013+0634 and WISE 0833+0052”, D. J. Pinfield et al, Monthly Notices of the Royal Astronomical Society, in press.

November 20, 2013December 23, 2015 by Elizabeth Howell

Human Spaceflight, Planetary Missions Face Potential Cuts in Latest NASA Budget Negotiations

While 2014 budget negotiations are not finalized yet, there’s already some noise of concern in different space communities that depend on NASA. Here’s a brief roundup of some of the news lately:

Could the Cassini Saturn mission get the axe? Wired’s Adam Mann warns that NASA may not be able to fund all of its planetary science missions in the coming year. Based on a statement that Jim Green, NASA’s planetary science director, made to an agency advisory council earlier this month, Mann narrows in on the Curiosity and Cassini missions as the big flagship missions that are requiring the most in terms of resources. Cassini is functioning perfectly and providing reams of data from Saturn and its moons, causing concern from planetary scientists about losing it early.

Only one commercial crew partner? NASA issued a cautious news release this week saying it is prepared to launch Americans from their own soil in 2017, “subject to the availability of adequate funding.” The agency is now moving into a new phase of its commercial crew program called Commercial Crew Transportation Capability (CCtCap), saying it is prepared to “award one or more CCtCap contracts no later than September 2014.” That means that the three companies currently funded — Boeing Co., Sierra Nevada Corp. and SpaceX — may face stiff competition for more money.

New report suggesting stopping NASA’s human spaceflight program: Before reading any further, do not jump to conclusions — making recommendations like this is a common practice by the Congressional Budget Office, which looks at all possibilities as it presents options for spending. Still, Space Politics’ Jeff Foust presents the report and generates some interesting comments after his story about the value of human spaceflight. For context, NASA and its international agency partners will need to make a decision fairly soon about continuing space station operations past 2020, so it’s possible the human spaceflight program could change.

What do you think of these proposals? Let us know in the comments.

November 20, 2013December 23, 2015 by David Dickinson

Get Out Your Comet Scorecards: Comet Nevski Now Visible With Binoculars

Capture of Comet Nevski shortly after discovery using the ITelescope Observatory in New Mexico. (Credit: Ernesto Guido, Nick Howes & Martino Nicolini).

Is 2013 truly the “Year of the Comet?” Perhaps “Comets” might be a better term, as no less than five comets brighter than +10^th magnitude grace the pre-dawn sky for northern hemisphere observers.

Comet C/2013 V3 Nevski has just brightened up 6 magnitudes — just over a 250-fold increase in brightness — and now sits at around magnitude +8.8. Comet Nevski was just recently discovered by Vitali Nevski using a 0.4 metre reflecting telescope 12 days ago on November 8^th. If that name sounds familiar, it’s because Nevski discovered the comet from the Kislovodsk observatory located near Kislovodsk, Russia which is part of the International Scientific Optical Network survey which located comet ISON last year. In fact, there was some brief controversy early on in its discovery that Comet C/2012 S1 ISON should have had the moniker Comet Nevski-Novichonok.

At the time of discovery, Comet Nevski appeared to be nothing special: shining at magnitude +15.1, it was well below our +10 magnitude limit for consideration as “interesting,” and was projected to linger there for the duration of its passage through the inner solar system. About a dozen odd such comet discoveries crop up per year, most of which give astronomers a brief pause as the orbit and size of the comet become better known, only to discern that they’re most likely to be nothing extraordinary.

The orbit of comet Nevski, as seen during the closest approach to the Earth on December 21st. (Credit: The Solar System Dynamics JPL Small-Body Database Browser).

Such was to be the case with Comet Nevski, until it suddenly flared up this past weekend.

Observer Gianluca Masi caught Comet Nevski in outburst, using a Celestron C14 remotely as part of the Virtual Telescope 2.0 project:

Comet Nevski captured on November 14th by Gianluca Masi. (Credit: The Virtual Telescope 2.0 Project).

You’ll note that Comet Nevski shows a small, spiky tail on the brief exposure. As of this writing, it currently sits at between magnitudes +8 and +9 and should remain there for the coming week if this current outburst holds.

Comet Nevski is well placed for northern hemisphere observers high in the morning sky, and will spend the remainder of November and early December crossing the astronomical constellation of Leo.

The celestial path of Comet Nevski from mid-November to the end of December. (Created by the author using Starry Night Education simulation software).

Here’s a blow-by-blow rundown on noteworthy events for this comet for the remainder of 2013:

November 23rd: Passes the +5.3 magnitude star Psi Leonis and crosses north of the ecliptic plane.

December 1st: Passes +3.4 magnitude star Eta Leonis.

December 6th: Passes +4.8 magnitude 40 Leonis and the bright +2nd magnitude star Algieba.

December 15th: Crosses into the constellation Leo Minor.

December 17th: Passes near the +5.5^th magnitude star 40 Leonis Minoris.

December 21st: Passes closest to Earth, at 0.847 Astronomical Units (A.U.s), or 126 million kilometres distant.

December 30th: Passes into the constellation Ursae Majoris.

Note that a “close pass” denotes a passage of the comet within a degree of a bright or interesting object.

The orbit of Comet Nevski is inclined 31.5 degrees relative to the ecliptic, and it will be headed for circumpolar for observers based in high northern latitudes as it dips back down below our “interesting” threshold of magnitude +10 in early 2014.

This comet passed perihelion on October 27^th, 2013 just over a week prior to discovery. Comet Nevski is Halley-type comet, with a 27.5 year orbit.

So, looking at the “Comet Scorecard,” we currently have:

Comet C/2012 X1 LINEAR: Still undergoing a moderate outburst at magnitude +8.2, very low to the north east for northern hemisphere observers at dawn in the constellation Boötes.

Comet 2P/Encke: Reaches perihelion tomorrow at 0.33 AU’s from the Sun, shining at magnitude +7.7 near Mercury in the dawn sky but is now mostly lost in the Sun’s glare.

Comet C/2013 R1 Lovejoy: is currently well placed in the constellation Ursa Major crossing into Canes Venatici in the hours before dawn. Currently shining at magnitude +5.4, Comet R1 Lovejoy is visible to the unaided eye from a dark sky site. We caught sight of the comet last week with binoculars, looking like an unresolved globular cluster as it passed through the constellations of Leo and Leo Minor.

And of course, Comet C/2012 S1 ISON: As of this writing, ISON is performing up to expectations as it approaches Mercury low in the dawn shining at just above +4^th magnitude. We’ve seen some stunning pictures as of late as ISON unfurls its tail, and now the eyes of the astronomical community will turn towards the main act: perihelion on November 28^th. Will it fizzle or dazzle? More to come next week!

The recent outbursts of Comets X1 LINEAR and V3 Nevski are reminiscent of the major outburst of Comet Holmes back in 2007. Of course, the inevitable attempts to link these outbursts to the current sputtering solar max will ensue, but to our knowledge, no conclusive correlations exist. Remember, the outburst from Comet Holmes occurred as we were approaching what was to become a profound solar minimum.

Also, it might be tempting to imagine that all of these comets are somehow related, but they are in fact each on unique and very different orbits, and only appear in the rough general direction in the sky as seen from our Earthly vantage point… a boon for dawn patrol sky watchers!

Got pics? Send ‘em in to Universe Today!

November 20, 2013December 23, 2015 by Elizabeth Howell

Asteroids Can Get Shaken And Stirred By Mars’ Gravity

Artist's conception of Mars, with asteroids nearby. Credit: NASA

Asteroids are sometimes called loose rubble piles, which leads to interesting effects if they happen to get close to a planet. A science team in 2010 found out that when asteroids get close to Earth, the gravity of our planet can stir up the dust grains and “refresh” its face, in a sense. Now, scientists have found that Mars can do the same thing.

Here’s the interesting part: the asteroid belt is in between Mars and Jupiter, which means that potentially more asteroids could be changed from the influence of Mars than what happens near Earth.

“Mars is right next to the asteroid belt, and in a way it gets more opportunity than the Earth does to refresh asteroids,” stated Richard Binzel, a professor of planetary sciences at the Massachusetts Institute of Technology who participated in both sets of research.

Artist’s impression of the asteroid (234) Barbara. Thanks to a unique method that uses ESO’s Very Large Telescope Interferometer, astronomers have been able to measure sizes of small asteroids in the main belt for the first time. Their observations also suggest that Barbara has a complex concave shape, best modelled as two bodies that may possibly be in contact. Credit: ESO/L. Calçada

“Picture Mars and an asteroid going through an intersection, and sometimes they’ll both come through at very nearly the same time,” Binzel added. “If they just barely miss each other, that’s close enough for Mars’ gravity to tug on [the asteroid] and shake it up. It ends up being this random process as to how these things happen, and how often.”

The initial research in 2010 showed that most asteroids are redder than meteorites. On asteroids, the surfaces get exposed to cosmic radiation and become redder as time goes on. But when as asteroid gets close to Earth, the planet’s gravity moves around the surface particles and brings fresher bits from underneath. Meteorites that break off from these asteroids would therefore not be as red.

This time around, Binzel’s team looked at other possibilities to “refresh” asteroids, such as collisions or energy from the sun, but concluded that the planets are probably the big reason we see the changed surfaces. You can read more details on the research in the journal Icarus or the preprint version on Arxiv. The lead author on the article was MIT planetary scientist Francesca DeMeo.

Source: MIT

November 20, 2013December 23, 2015 by Elizabeth Howell

What Day 1 On The International Space Station Was Like For The Astronauts

Astronaut Jerry Ross during one of three December 1998 spacewalks to get the space station ready for human habitation. Reflected in his helmet is NASA astronaut James Newman. Behind is one of the solar arrays for the Russian Zarya module. Credit: NASA

There wasn’t a lot of elbow room when six people from the Endeavour shuttle floated into the baby International Space Station on Dec. 10, 1998, but the cramped quarters resonated with possibility in STS-88 commander Bob Cabana’s mind.

“It’s hard to believe 15 years ago we put those first modules together, and we have this facility today that’s the size of a football field,” said Cabana in an interview today (Nov. 20) with Universe Today.

Cabana, who is now the director of the Kennedy Space Center, oversaw a complex mission that included joining the Russian Zarya and U.S. Unity modules, three spacewalks to get the modules powered and ready for humans to enter, and the pressure of public relations activities surrounding the opening of the station itself.

“That was a very special day, when we went into Unity and Zarya for the first time. There was a lot of excitement and anticipation,” Cabana said. He and Russian Sergei Krikalev — who would go on to become the person who spent the most time in space, at 803 days — entered the tiny hatches side by side to emphasize the international participation.

As is typical of spaceflight, the astronauts spent most of their day at work, busily waking up the station and testing its systems. NASA astronauts Jerry Ross and James Newman put together a communications system. Other crew members tested the videoconference equipment — important for press conferences as well as talking to scientists on the ground. Equipment and supplies in Zarya had to be unstowed and organized.

There also was the first repair on station, when Krikalev and NASA astronaut Nancy Currie replaced a faulty unit in Zarya “which controlled the discharging of stored energy from one of the module’s six batteries,” NASA wrote in an update at the time.

Cabana wanted his crew to get eight hours of sleep, but the excitement of that first day kept everybody up until 2:30 in the morning despite the wakeup call coming at 7 a.m.

A space station is born. The Russian Zarya module (top) is connected to the U.S. Unity module using the Canadarm on Dec. 6, 1998. Shot is a still from an IMAX camera carried on board shuttle Endeavour. Credit: NASA

“We were talking about what the ISS means, what will be accomplished with this cornerstone,” Cabana recalled, and said he is pleased with what has come to pass in the next 15 years. “It had come true. Everything we thought that could be has come together. That was a very special night, thinking about the future and how important the International Space Station was.”

The heaviest construction finished in 2011, and larger crews of six were allowed on board rather than the beginning crews of just three. NASA is now trying to position the station as a venue for microgravity science to justify the expense of running it. The astronauts, however, must balance their time doing science with the normal chores and maintenance the station requires. (The recent Expedition 35/36 missions were extremely productive in terms of science return, NASA astronaut Chris Cassidy told Universe Today in a past interview.)

All buildings on Earth require upgrades from time to time to stay safe and up to date, and the ISS is no different. Cabana said analysis will be done to “extend the life on some of the modules, but we don’t see that as a large issue.” The reason? The crews do “an outstanding job” keeping the station humming along with routine maintenance, he said.

Today (Nov. 20) marks the 15th anniversary of Zarya’s launch into orbit. The station partners are currently committed until 2020, meaning negotiations are forthcoming to see what to do with the station in the years afterwards. It’s unclear what will happen next — the recession is still reverberating in the United States and overseas — but today, the agencies focused on the successes.

Each partner agency tweeted facts and science concerning the ISS under the hashtag #ISS15, and invited people using all forms of social media to share their thoughts on the station. What are some notable things about the station, and what is a good use of it in the future, in your opinion? Let us know in the comments.

NASA astronaut Bob Cabana (left) and Russian cosmonaut Sergei Krikalev just outside the hatch to the Zarya Russian module on Dec. 10, 1998. Credit: NASA

November 20, 2013December 23, 2015 by Nancy Atkinson

NASA Infographic: 15 Years of the International Space Station

The first International Space Station component, the Russian Zarya module, was launched 15 years ago today, on November 20, 1998. Since then, a consortium of 15 different nations have constructed a world-class orbiting laboratory, with a continual human presence onboard since 2000. Construction was considered officially complete in 2011, but new modules are still planned.

NASA is celebrating the milestone with an infographic showcasing some of the amazing and surprising facts about humanity’s home away from Earth. See below for the infographic, as well as two videos with highlights from the past 15 years of the ISS:

To keep tabs on what is going on daily at the ISS, visit NASA’s ISS webpage. You can also find out how to see the station for yourself at spotthestation.nasa.gov or watch live station video at www.nasa.gov/iss-stream.

November 19, 2013December 23, 2015 by Nancy Atkinson

Win a Copy of The Year in Space: 2014 Wall Calendar

It’s back! And it’s full of amazing color images, daily space facts, historical references, and it even shows you where you can look in the sky for all the best astronomical sights. The 2014 version of Steve Cariddi’s wonderful Year in Space Wall Calendar is now available to order, and thanks to Steve, Universe Today has 5 copies to give away!

This giveaway is now closed.

This is a gorgeous wall calendar that has over 120 beautiful photos of space, as well as in-depth info on human space flight, planetary exploration, and deep sky wonders. This calendar is huge — much larger than a traditional wall calendar — and last year it was named “Science Geek Gift of the Year” at Alan Boyle’s NBC “Cosmic Log” website.

Other features of this calendar:
– Background info and fun facts
– A sky summary of where to find naked-eye planets
– Space history dates
– Major holidays (U.S. and Canada)
– Daily Moon phases
– A mini-biography of famous astronomer, scientist, or astronaut each month

For our giveaway, to be entered into the drawing, just put your email address into the box below (where it says “Enter the Giveaway”) before Monday, November 25, 2013.

If this is the first time you’re registering for a giveaway from Universe Today, you’ll receive a confirmation email immediately where you’ll need to click a link to be entered into the drawing. For those who have registered previously, you’ll receive an email later where you can enter this drawing.

These calendars normally sell for $16.95, but Universe Today readers can buy the calendar for only $12.95 or less (using the “Internet” discount), and get free U.S. shipping and discounted international shipping.

There’s also the 144-Page Desk Calendar at a similar discounts.

You can preview the entire calendar at the Year in Space Calendar website.

It’s published in cooperation with The Planetary Society, with an introduction by Bill Nye. Our thanks to Steve Cariddi for providing this giveaway opportunity for our readers!

November 19, 2013December 23, 2015 by Ken Kremer

How to Watch the Spectacular Minotaur Night Launch on Nov. 19 with Record Setting 29 Satellite Payload

Elevation viewing map for Minotaur 1 rocket launch on Nov. 19 from NASA Wallops Island facility. Credit: Orbital Sciences

Tonight, Tuesday, Nov. 19, tens of millions of residents up and down the US East coast have another opportunity to watch a spectacular night launch from NASA’s Wallops Island facility in Virginia – weather permitting.

See a collection of detailed visibility and trajectory viewing maps, as well as streaming video of the launch, courtesy of rocket provider Orbital Sciences and NASA Wallops Flight Facility.

And to top that off, the four stage Minotaur 1 rocket is jam packed with a record setting payload of 29 satellites headed for Earth orbit.

And if that’s not enough to pique your interest, the Virginia seaside launch will also feature the first cubesat built by high school students.

And viewing is open to the public.

Minotaur 1 launch trajectory map for the US Capitol, Washington, DC. Credit: Orbital Sciences

Blastoff of the Minotaur I rocket for the Department of Defense’s Operationally Responsive Space Office on the ORS-3 mission is on target for tonight, Nov. 19, from the Mid-Atlantic Regional Spaceport’s Pad-0B at NASA’s Wallops Flight Facility on the eastern shore of Virginia.

The launch window for the 70 foot tall booster opens at 7:30 pm EST and extends until 9:15 pm EST.

Minotaur 1 launch trajectory map for Rockefeller Center N.Y.C.

The ORS-3 mission is a combined US Air Force and NASA endeavor that follows the flawless Nov. 18 launch of NASA’s MAVEN Mars orbiter from Florida by just 1 day.

However the pair of East coast launch pads are separated by some 800 miles.

Minotaur 1 launch trajectory map for Charleston S.C.

According to NASA and Orbital Sciences, the launch may be visible along a wide swatch from northern Florida to southern Canada and well into the Midwest stretching to Indiana – if the clouds are minimal and atmospheric conditions are favorable from your particular viewing site.

The primary payload is the Space Test Program Satellite-3 (STPSat-3), an Air Force technology-demonstration mission, according to NASA.

Minotaur 1 launch trajectory map for Raleigh N.C.

Also loaded aboard are thirteen small cubesats being provided through NASA’s Cubesat Launch Initiative, NASA said in a statement. Among the cubesats is NASA’s Small Satellite Program PhoneSat 2 second generation smartphone mission and the first ever cubesat assembled by high schooler’s.

Minotaur 1 launch trajectory map for Philadelphia P.A.

Locally, the NASA Visitor Center at Wallops and the Chincoteague National Wildlife Refuge/Assateague Island National Seashore will be open for viewing the launch. Visitors to Assateague need to be on the island by 6 p.m. before the entrance gate closes.

Live coverage of the launch is available via UStream beginning at 6:30 p.m. EST on launch day. Watch below:

Ken Kremer

November 19, 2013December 23, 2015 by Shannon Hall

Using the ‘Missing Physics’ of Stellar Feedback to Accurately Simulate Galaxies from the Big Bang to Today

A simulated dwarf galaxy when the universe was 0.5 billion years old. Magenta represents cool gas, green is warm ionized gas, and red is hot gas. Check out the movie. Image credit: Hopkins et al. 2013.

For the first time, astronomers are able to accurately simulate galaxies from shortly after the big bang to today by including a realistic treatment of the effects stars have on their host galaxies.

For the past few decades astronomers have simulated galaxies by mixing the basic physical ingredients — gravity, gas chemistry and the evolution of the universe — into their models.

For years their simulations have shown that gas cools off quickly and falls to the center of the galaxy. Eventually all of the gas forms stars. But observations show only “10 percent of the gas in the universe actually does so,” CalTech astronomer Dr. Philip Hopkins explained. “And in very small or very large galaxies, the number can go down to well below a percent.”

Models of galaxies create far too many stars and as a result end up weighing more than real galaxies in the observable universe. But in theory the solution is simple: the missing physics is a process known as stellar feedback.

For that, astronomers have to look at how stars help shape the evolution of the galaxies in which they reside. And what they have found is that stars affect their environments drastically.

When stars are very young they are extremely hot and blast off a high amount of radiation into space. This radiation heats up and pushes on the nearby interstellar gas. Later on stellar winds – particles streaming from the surface of stars — also push on the gas, further disrupting nearby star formation. Finally, explosions as supernovae can push the gas to nearly sonic speeds.

While astronomers have understood the missing physics for quite a while, they have not been able to successfully incorporate it a priori into their models. Despite their efforts their simulated galaxies have always weighed more than observed galaxies actually weigh.

Understanding the missing physics is a completely different question than being able to incorporate the missing physics directly into their models.

Instead, astronomers made big assumptions based on what galaxies should look like. At some point in their simulations, they had to go in by hand and tune certain parameters. They would get rid of so much gas until the results roughly matched the galaxies we observe.

“Basically, they (astronomers) said ‘we need there to be winds to explain the observations, so we’re going to insert those winds by hand into our models, and adjust the parameters until it looks like what’s observed,’ ” Hopkins told Universe Today.

At the time tuning their models in this way was the best astronomers could do and their models did help improve our understanding of galaxy evolution. But Hopkins and a team of astronomers from across North America have found a way to incorporate the missing physics — stellar feedback — directly into their models.

The research team is creating simulations that draw from stellar feedback explicitly. The FIRE (Feedback in Realistic Environments) project is a multi-year, multi-institution effort.

While it was no easy task, they incorporated the necessary and dare I say messy physics into their models, allowing for unprecedented accuracy. They tracked the affects radiation and stellar winds have on their environments and included a realistic supernovae rate.

“The result is that we see these stars pushing on the gas, and supernovae explosions sweeping up and ‘blowing out’ large amounts of material from galaxies,” Hopkins explained. “When you follow all of this, the story holds together, and indeed we can explain the observed masses of galaxies just from the input of stars.”

A simulated galaxy when the universe was 11.7 billion years old. Make sure the check out the move by clicking on the image above. Image credit: Hopkins et al. 2013 — A simulated galaxy when the universe was 11.7 billion years old. Blue regions are young star clusters that have blown away their gas. Red regions are obscured by dust. Make sure the check out the movie by clicking on the image above. Image credit: Hopkins et al. 2013.

The results have been rewarding — providing some pretty cool videos of galaxies forming across the observable universe — and surprising.

It has become clear that the different types of stellar feedback don’t work alone. While the energy given off by stellar winds can push away interstellar gas, it cannot launch the gas out of the galaxy entirely. The necessary propulsion occurs, instead, when a supernova explosion happens nearby.

But this isn’t to say that supernova explosions play a larger role than stellar winds. If the authors left out any stellar feedback mechanism (the radiation from hot young stars, stellar winds, or supernova explosions) the results were equally poor — with too many stars and masses much too large.

“We’ve just begun to explore these new surprises, but we hope that these new tools will enable us to study a whole host of open questions in the field.”

The paper has been submitted for publication in the Monthly Notices of the Royal Astronomical Society and is available for download here.

Hopkins discusses the “Cosmological zoom-in simulation using new stellar feedback” at at workshop at the University of California, Santa Cruz earlier this year:

November 19, 2013December 23, 2015 by Elizabeth Howell

Moonwalker’s Golf Club Now Hanging Out In New Jersey Museum

Apollo 14 astronaut Al Shepard holding a golf club he used during the moon mission in 1971. Here he is visiting the United States Golf Association Museum in Far Hills, NJ in 1995. Credit: Robert Walker/USGA

During that heady time when NASA was sending people to the moon, Apollo astronaut Al Shepard — so the story goes — was showing comedian Bob Hope around a NASA center. Hope went into a simulator for the lighter lunar gravity and swung a golf club around (a habit of his) as he bounced around.

“That was the inspiration, I guess,” said Michael Trostel, the curator and historian at the United States Golf Association Museum in Far Hills, New Jersey. In other words, the inspiration for Al Shepard to bring a golf club to the moon and hit a couple of balls. The golf club, in fact, is at the USGA Museum today.

Of course, it wasn’t so easy just to bring a six-iron on board — there were science experiments and other payloads for the Apollo 14 crew. According to the Smithsonian National Air and Space Museum, the golf club was actually “a contingency sample extension handle with a No. 6 iron golf club head attached.”

Unusually, as space artifacts tend to head over to the Smithsonian after missions, this particular one ended up at the USGA Museum itself. In 1972, when singer Bing Crosby (also a friend of Hope’s and Shepard’s) was a member of the board, he wrote to Shepard on behalf of the museum and asked for the club. Shepard agreed and handed it over during a special ceremony in 1974.

“The reason that it’s not in this museum was that it was personal property of Alan Shepherd. In other words, he took it to space, he brought it back, it was still his personal property he donated it and it was his. That’s the reason,” said Claire Brown, the Smithsonian National Air and Space Museum’s communications director.

“Things were a little different back then. You could take a certain amount of personal property. There are different rules now, but at the time that he did it, he was able to bring his own personal club.”