Hello Universe Today commentators! I just wanted to let you know that I’ve decided to disable Disqus comments on Universe Today, and return to plain old WordPress comments. There are a bunch of reasons why I decided to do this, most around my nervousness about having comments hosted outside Universe Today.
As you’ve probably noticed, I’ve struggled for years about what to do with comments on the website. I’ve tried lots of different plugins and services, searching for the right option. Continue reading “Back to Regular WordPress Comments”
Orbiting near a moving black hole doesn't seem like the safest mode of transportation, but time dilation might make it worth the risk. Credit: NAOJ
If you could get a good look at the environment around a supermassive black hole — which is a black hole often found in the center of the galaxy — what factors would make that black hole keep going?
A Japanese study revealed that at least one of these black holes stay “active and luminous” by gobbling up nearby material, but notes that only a few of the observed galaxies that are merging have these types of black holes. This must mean something unique arises in the environment near the black hole to get it going, the researchers say. What that is, though, is still poorly understood.
Supermassive black holes, defined as black holes that have a million times the mass of the sun or more, reside in galaxy centers. “The merger of gas-rich galaxies with SMBHs [supermassive black holes] in their centers not only causes active star formation, but also stimulates mass accretion onto the existing SMBHs,” stated a press release from the Subaru Telescope.
“When material accretes onto a SMBH, the accretion disk surrounding the black hole becomes very hot from the release of gravitational energy, and it becomes very luminous. This process is referred to as active galactic nucleus (AGN) activity; it is different from the energy generation activity by nuclear fusion reactions within stars.”
Figuring out how these types of activity vary would give a clue as to how galaxies come together, the researchers said, but it’s hard to see anything in action because of dust and gas blocking the view of optical telescopes. That’s why infrared observations come in so handy, because it makes it easier to peer through the debris. (You can see some examples from this research below.)
Examples of infrared K-band images of luminous, gas-rich, merging galaxies. Credit: NAOJ
The team (led by the National Astronomical Observatory of Japan’s Masatoshi Imanishi) used NAOJ’s Subaru’s Infrared Camera and Spectrograph (IRCS) and the telescope’s adaptive optics system in two bands of infrared. Researchers looked at 29 luminous gas-rich merging galaxies in the infrared and found “at least” one active supermassive black hole in all but one of the ones studied. However, only four of these galaxies merging had multiple, active black holes.
“The team’s results mean that not all SMBHs in gas-rich merging galaxies are actively mass accreting, and that multiple SMBHs may have considerably different mass accretion rates onto SMBHs,” Subaru stated.
The implication is more about the environment around a supermassive black hole must be understood to figure out how mass accretes. Knowing more about this will improve computer simulations of galaxy mergers, the researchers said.
Expedition 38 cosmonaut Oleg Kotov during a January 2014 spacewalk, outside the Zvezda service module. Credit: NASA TV
UPDATE: As of Tuesday morning (Eastern time), UrtheCast announced that telemetry was successfully received, “contrary to the online broadcast of the installation.” CEO Scott Larson added that his company “can now focus on the routine commissioning of the cameras in preparation for the unveiling of our Ultra HD, color video of Earth.” Below is the report from Monday.
A second crack at installing the UrtheCast cameras on the International Space Station also ran into data trouble, according to a press release from NASA, although the company involved with the cameras says it is still waiting for more information about the telemetry.
Expedition 38 spacewalkers Oleg Kotov and Sergey Ryazanskiy were again trying to put the cameras outside the station for UrtheCast to provide live views of Earth to subscribers. The cosmonauts’ first attempt on Dec. 27 showed telemetry problems, at which point the spacewalkers were instructed to bring the cameras back inside.
“The duo translated to the Zvezda service module and installed a high-resolution camera and a medium-resolution camera to capture Earth imagery. However, the medium resolution camera again experienced telemetry issues,” NASA stated.
On Twitter, however, UrtheCast stated that it is still awaiting confirmation on the status of the telemetry. We’ll keep you posted when they issue an update.
Kotov and Ryazanskiy spent six hours, eight minutes outside performing this and other routine tasks, marking the fourth spacewalk in about a month for Expedition 38. Besides the other Russian spacewalk in late December, two American astronauts ventured out close to Christmas to make a contingency swap on a faulty ammonia pump.
The crew of Challenger, lost on January 28, 1986. Credit: NASA.
It was on this day (Jan. 28) in 1986 that stunned viewers across the world saw the Challenger space shuttle explode on television. The broadcast (you can see CNN’s above) was being carried all over the place because the crew included the first teacher in space, Christa McAuliffe. The planned six-day mission, however, lasted just over a minute before catastrophe occurred.
Flying aboard mission 51-L were commander Francis “Dick” Scobee, pilot Michael Smith, mission specialists Judith Resnik, Ellison Onizuka and Ronald McNair, and payload specialists Gregory Jarvis and McAuliffe. The physical cause of the explosion was traced back to a faulty O-ring on one of the shuttle’s external boosters, which weakened in the cold before launch and then failed, leading to the explosion about 72 seconds after launch.
Other factors were cited as well by journalists and the Rogers Commission, such as NASA’s desire to keep to what outsiders said was an unrealistic, quick-moving launch schedule that saw shuttles leave the ground every few weeks to carry commercial and military payloads. NASA and contractor Morton Thiokol made changes to the boosters, and NASA further changed the flight rules and other procedures in response to the disaster.
There are many memorials to the fallen crew, but one of the most cited in education is the 40 Challenger Learning Centers that are located in the United States, Canada, United Kingdom and South Korea. The network was founded by June Scobee Rogers (the widow of commander Scobee) and includes participation from other Challenger family members. Their goal is to “give students the chance to become astronauts and engineers and solve real-world problems as they share the thrill of discovery on missions through the Solar System,” the website states.
Challenger’s anniversary comes in a week that includes other tragic anniversaries, including the Apollo 1 pad fire that claimed three astronauts’ lives (Jan. 27, 1967) and Columbia shuttle breakup that killed seven (Feb. 1, 2003). Other astronauts have died in training accidents; you can see a list at the Astronaut Memorial Foundation. Additionally, four cosmonauts died in spaceflight: Vladimir Komarov (Soyuz 1 on April 24, 1967) and Georgi Dobrovolskiy, Viktor Patsayev, and Vladislav Volkov (Soyuz 11 on June 30, 1971).
The Challenger space shuttle a few moments after the rupture took place in the external tank. Credit: NASA
The spiral galaxy NGC 6946 and its smaller companions are found to be surrounded by "cold rivers" of hydrogen
What happens when a galaxy doesn’t have enough hydrogen to support its stellar production process? Why, it sucks it from its hapless neighbors like some sort of cosmic vampire, that’s what. And evidence of this predatory process is what’s recently been observed with the National Science Foundation’s Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, in the form of faint “cold flows” bridging intergalactic space between the galaxy NGC 6946 and its smaller companions.
“We knew that the fuel for star formation had to come from somewhere,” said astronomer D.J. Pisano from West Virginia University, author of the study. “So far, however, we’ve detected only about 10 percent of what would be necessary to explain what we observe in many galaxies. A leading theory is that rivers of hydrogen – known as cold flows – may be ferrying hydrogen through intergalactic space, clandestinely fueling star formation. But this tenuous hydrogen has been simply too diffuse to detect, until now.”
NGC 6946 also goes by the festive moniker of “the Fireworks Galaxy,” due to the large amount of supernovae that have been observed within its arms — eight within the past century alone. Located 22 million light-years away between the constellations Cepheus and Cygnus, NGC 6946’s high rate of star formation has made astronomers curious as to how it (and other starburst galaxies like it) gets its stellar fuel.
One long-standing hypothesis is that large galaxies like NGC 6946 receive a constant supply of hydrogen gas by drawing it off their less-massive companions.
Chandra and Gemini image of NGC 6946 (X-ray: NASA/CXC/MSSL/R.Soria et al, Optical: AURA/Gemini OBs)
Now, thanks to the GBT’s unique capabilities — such as its immense single dish, unblocked aperture, and location in the National Radio Quiet Zone — direct observations have been made of the extremely faint radio emissions coming from neutral hydrogen flows connecting NGC 6946 with its smaller satellite galaxies.
According to a press release from the National Radio Astronomy Observatory:
Earlier studies of the galactic neighborhood around NGC 6946 with the Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands have revealed an extended halo of hydrogen (a feature commonly seen in spiral galaxies, which may be formed by hydrogen ejected from the disk of the galaxy by intense star formation and supernova explosions). A cold flow, however, would be hydrogen from a completely different source: gas from intergalactic space that has never been heated to extreme temperatures by a galaxy’s star birth or supernova processes.
Another possible source of the cold flow is a previous collision with another galaxy, possibly even one of its own satellites, which would have left strands of atomic hydrogen in its wake. But if that were the case stars would likely have since formed within the filaments themselves, which has not yet been observed.
Image credit: D.J. Pisano (WVU); B. Saxton (NRAO/AUI/NSF); Palomar Observatory – Space Telescope Science Institute 2nd Digital Sky Survey (Caltech); Westerbork Synthesis Radio Telescope
Looking west on January 31st 30 minutes after sunset. (Created using Stellarium).
There’s an often told anecdote that astronomer Nicolaus Copernicus never spied Mercury. And while this tale is almost certainly apocryphal, it does speak to just how elusive the innermost planet of our solar system really is.
Never seen Mercury for yourself? This final week of January offers a good time to try, as Mercury reaches greatest elongation east of the Sun on Friday, January 31st.
This will offer northern hemisphere viewers one on the best chances to spot the fleeting world low to the west immediately after local sunset. And although we get on average six apparitions of Mercury per year – three each in the dawn and dusk – all apparitions aren’t created equal.
The approximate moment of greatest elongation occurs on January 31st at 10:00 UT / 5:00 AM EST, when Mercury is 18.4 degrees east of the Sun. This is only 0.5 degrees shy of the smallest elongation for Mercury that can occur, as the planet reaches perihelion just three days later on February 3rd at 0.3075 Astronomical Units (AUs) from the Sun. The last time this was surpassed was the evening elongation of February 16th, 2013th, and the next time it’ll be topped is October 16th, 2015 at just 18.1 degrees from the Sun.
Path of Mercury from January 27th to February 12th as seen from latitude 30 degrees north. (Created using Starry Night Education Software).
And though this elongation is closer than usual, this also works in the Mercury-spotter’s favor. At greatest elongation, Mercury will present a 50% illuminated 7 arc second disk, readily apparent in a small telescope. But a also means that Mercury will appear almost a full magnitude brighter than it does when it reaches greatest elongation near aphelion, as it last did on March 31st of last year, and will do again on March 14th of this year.
Mercury will shine at magnitude -0.4 low towards the west into this coming weekend. We managed to pick up Mercury with binoculars on January 16th and have since managed to start tracking the planet unaided since January 18th.
Mercury also has another factor going for it, in terms of the angle of the evening ecliptic. Following ahead of the Sun, Mercury occupies a space that the Sun will trace up its apparent path along the ecliptic as it begins its long slow crawl northward towards the Vernal Equinox on March 20th. This means that Mercury is almost perpendicular above the western horizon at dusk and is currently getting a maximum boost above the atmospheric murk.
Mercury also gets joined by a razor thin waxing crescent Moon just over 24 hours past New sliding by it on the evening of Friday, January 31st. Look for the Moon five degrees to the right of Mercury on the 31st. The Moon will be a much easier catch on the February 1st when its 10 degrees above Mercury. And can you spy the +1 magnitude star Fomalhaut in the constellation Piscis Austrinus just 20 degrees to the south of Mercury?
The orientation of the Moon and Mercury on the evening of February 1st. Credit: Stellarium.
And speaking of the Moon, this week’s New Moon is the second of the month, a feat that repeats in March 2014 and leaves the month of February “New Moon-less…” such an occurrence in either instance is informally known as a Black Moon.
Orbiting the Sun once every 88 days, Mercury completes about 4.15 circuits of the Sun for every Earth year. From our Earthbound vantage point, however, Mercury seems to only orbit the Sun 3.15 times a year. Thus 6 elongations (3 in the dusk and 3 in the dawn) will occur every year, through 7 can occur, as last happened in 2011 and will occur again next year in 2015.
Mercury (to the lower left) and the Moon on August 15th, 2012. (Photo by author).
After this weekend, Mercury will resume its plunge towards the horizon through early February. Mercury will begin retrograde (westward) apparent motion against the starry background on February 6th before resuming direct (eastward motion) on February 27th. And although astrologers may find that “Mercury in retrograde” is a convenient “blame magnet,” they’re also falling prey to a logical fallacy known as retrofitting, as Mercury spends a longer fraction of time than any other planet “in retrograde” at about 20%!
From there, Mercury heads towards inferior conjunction between the Earth and the Sun on Saturday, February 15th, passing just 3.7 degrees north of the solar disk. You can catch Mercury entering into the field of view of the Solar Heliospheric Observatory’s (SOHO) LASCO C3 camera from February 12th to February 18th.
And although Mercury misses this time, we’re not that far away from the next transit of Mercury across the face of the Sun on May 9th, 2016.
Up for more? An even tougher challenge is to attempt to spot Mercury… in the daytime. We’ve noted this possibility before as Mercury reaches maximum elongation from the Sun while still in the negative magnitude range. Of course, you want to physically block the Sun out of view, and don’t even try sweeping the sky near the Sun visually with binoculars or a telescope! You’ll need a clear, blue sky for maximum contrast and a polarizing filter may help in your quest… but this should be possible under exceptional conditions.
Good luck, and be sure to send those Mercury pics in to Universe Today!
Artist's impression of New Horizons' encounter with Pluto and Charon. Credit: NASA/Thierry Lombry
Less than a year from now, the New Horizons spacecraft will begin its encounter with Pluto. While closest approach is scheduled for July 2015, the Long Range Reconnaissance Imager or “LORRI” will begin snapping photos of the Pluto system six months earlier.
This first mission to Pluto has been a long time coming, and this new “trailer” put out by the New Horizons team recounts what it has taken to send the fastest spacecraft ever on a 5 billion km (3 billion mile) journey to Pluto, its largest moon, Charon, and the Kuiper Belt beyond. The spacecraft has been zooming towards the edge of our Solar System for over eight years since it launched on January 19, 2006.
By late April 2015, the approaching spacecraft will be taking pictures of Pluto that surpass the best images to date from Hubble. By closest approach in July 2015 –- when New Horizons will be 10,000 km from Pluto — a whole new world will open up to the spacecraft’s cameras. If New Horizons flew over Earth at the same altitude, it’s cameras could see individual buildings and their shapes.
“Humankind hasn’t had an experience like this–an encounter with a new planet–in a long time,” said Alan Stern, New Horizons’ principal investigator. “Everything we see on Pluto will be a revelation.”
It’s likely there could be some new planetary bodies discovered during the mission in addition to the five known moons: Charon, Styx, Nix, Kerberos, and Hydra.
“There is a real possibility that New Horizons will discover new moons and rings as well,” says Stern.
No matter what, Stern said, this is going to be an amazing ride.
“We’re flying into the unknown,” he said, “and there is no telling what we might find.”
See the countdown clock and find out more about the mission at the New Horizons website.
And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.
Orion steps above towering spruce on a January evening. Credit: Bob King
Bitter cold lies ahead for many skywatchers in the U.S. and Canada in the coming week as the polar vortex swoops down from Santa’s village for round two this season. Will that stop you from going out to enjoy the winter wonders of Jupiter, the M82 supernova and Orion? It needn’t if you take the proper precautions.
In all honesty, you’ll probably still get cold if you attempt to observe on windy, subzero nights, but if you follow these helpful hints, you won’t get as cold. That said, there are two key ingredients to a successful and happy night under the winter sky: dressing well and planning in advance what you want to see.
I know it looks like an alien abduction with only the clothes left behind, but consider this an illustration of good nighttime winterwear. Credit: Bob King
Dressing well means having to accept the fact that even though you still feel warm walking out the door, 10 minutes later you won’t be. Always layer to the hilt. Insulated pack boots like those made by Sorrel or LaCrosse will keep your feet toasty for at least an hour of standing in place at the telescope.
I still wear blue jeans during winter, but when out getting a winter star tan, I pull on a pair of insulated snow pants. To keep heat from escaping the rest of the body, a flannel shirt, thick sweater and some kind of down or insulated coat will provide protection right up to your neck. Some folks like the all-in-one approach and don a snowmobile suit. Add a scarf, a bomber cap with furry ear flaps for the head region and lined mittens or gloves for your digits, and you’re almost ready to do battle. Assuming you still have energy left after building a fortress around your person.
Tuck chemical hand warmer packets inside your gloves or boots. Credit: Bob King
About gloves. I use lined deerskin gloves with chemical hand-warmers nestled in each palm. It’s so nice to have something warm to push your fingers into when they get chilled. Others prefer the wiser dual-glove approach – wearing a pair of thin gloves inside mittens that Velcro open across the palm. That way you use your fingers to adjust focus or check a chart and then safely tuck your hands back into the mittens.
On super-cold nights I’ll set the telescope up right outside the house so I can bail when necessary, but on exceptional nights when it might be well below zero but not windy, I’ll make the drive to the country for darker skies and set up on the proverbial road in the middle of nowhere.
I limit my observing to two hours maximum. Not because I have any control over time; that’s as much as this body can take when it’s -20 F. One little trick I’ve employed over the years to survive astronomical cold is to keep moving. I check charts constantly, set eyepieces down in the trunk of the car, then return to pick up a different eyepiece, take a short walk and even run in place. Hey, only the wolves are watching, so who cares? All this to keep the body moving to generate heat.
On very cold nights it’s a good idea to make a concise observing plan to efficiently use your time at the telescope. I grab a few charts and often take brief notes outside using a red flashlight. Credit: Bob King
If I do freeze, the car provides some solace. A typical drive home will find me steering with my inner arms, my crabbed hands straining to absorb every molecules of hot air blasting from the vents
The second key ingredient to a successful, soulful, subzero night is planning. If you prepare a short list either on paper or mentally of winter sky gems before you walk out the door, you’ll spend your stellar minutes more efficiently and return indoors a happy camper.
I keep it simple. If there’s a bright planet out, that’s always on my list. With Jupiter shining so enticingly these nights, how can you not go out to see what the weather’s doing on the solar system’s biggest planet? Relish the thought that the cloud tops you’re seeing are cold enough at -230 F (-145 C) to snow ammonia flakes. Makes 20 below almost seem like shirtsleeve weather.
A well-dressed stargazer relishes a night under the winter stars. Credit: Bob King
Add in a few variable stars, a supernova, maybe a comet and two or three deep sky objects and I feel a sense of connection and accomplishment by the time I return inside to what now feels like a Hawaiian vacation in my living room. Total time elapsed: maybe an hour. Too much? 15 minutes for a pretty double star and a current planet will do. Astronomy photos, articles and book are great, but we all need the real thing from time to time; there’s no substitute for a direct connection to the cosmic wilderness.
One crucial tip on doing astronomy in winter. Make sure your telescope is COLD. A spare meat locker for storage would be ideal. Barring that, place the scope outside and let it cool down before you begin your observing session. If it comes directly from the house, 45 minutes to an hour should be enough, depending on the temperature and aperture size. If you store it in a garage or shed, 20 minutes should do the trick.
A brilliant moonlit night in January with the Big Dipper rising in the northeastern sky. Credit: Bob King
Ready to zip up? Go for it! I ran into a woman a couple weeks back who told me she loved winter because the cold made her feel alive. Man, she hit it right on the head. I’ll leave you with a quote from one of my favorite old-time authors, Joseph Elgie, an English amateur astronomer who wrote about the pleasures of the sky no matter the season in a book titled The Night Skies of a Year. This entry is from February about the year 1907:
“Shortly after nine o’clock Procyon could be seen through the openings in the flying clouds, not far from the meridian. The sky resembled a vast snow-field in swift motion – a snow field showing fleeting patches of blue, which were studded with sparklets of silver, and Procyon was one of those sparklets. In the sou’west too, I could discern a coppery gleam on the pale blue background of the sky. It was Betelgeuse. What pictures of tender loveliness were these!”
Images of M82 show the supernova after discovery, compared with an earlier image. Credit: UCL/University of London Observatory/Steve Fossey/Ben Cooke/Guy Pollack/Matthew Wilde/Thomas Wright
In a rare example of cloudy weather helping astronomy rather than hurting it, the team that found M82’s new supernova swung a telescope in that direction only because their planned targets for the night were obscured, a release stated.
The exploding star in the “Cigar Galaxy” was found at 7:20 p.m. UTC (2:20 p.m. EST) during a class taught by Steve Fossey at the University of London Observatory. Students Ben Cooke, Tom Wright, Matthew Wilde and Guy Pollack all participated in the discovery.
“The weather was closing in, with increasing cloud,” recalled Fossey in a press release, “so instead of the planned practical astronomy class, I gave the students an introductory demonstration of how to use the CCD camera on one of the observatory’s automated 0.35–metre [1.14-foot] telescopes.”
The new supernova in M82 captured by the 32-inch Schulman Telescope (RCOS) at the Mount Lemmon Sky Center in Arizona on January 23, 2014. Credit and copyright: Adam Block/Mount Lemmon SkyCenter/University of Arizona
The students asked for M82, at which point Fossey saw a star that he couldn’t recall from examining the galaxy previously. A search of other images online revealed that something strange was happening, but clouds were obscuring everything quickly. The team focused on taking one- and two-minute exposures with different filters, and also using a second telescope to make sure there wasn’t something wrong with the first.
The team checked for any reports of a supernova, and finding none, Fossey sent a message to the International Astronomical Union’s Central Bureau for Astronomical Telegrams (which catalogs supernovae) and a United States team that does regular searches for exploding stars. Among his concerns was that it could be an asteroid lying in the way of the galaxy, but further spectroscopic measurements confirmed the “fluke” find, the release added.
The great thing about SN 2014J is it’s visible even in small telescopes. It’s also fairly close, by astronomical standards, at about 12 million light-years away. (The closest found since the invention of the telescope was Supernova 1987A, which exploded in February 1987 and was 168,000 light-years away.) Astrophotographers have already snapped many images of the exploding star.
“One minute we’re eating pizza, then five minutes later we’ve helped to discover a supernova,” stated Wright. “I couldn’t believe it. It reminds me why I got interested in astronomy in the first place.”
