The folks over at PHD Comics have put together a new video in their Two-Minute Thesis series, this one featuring Ph.D candidate Or Graur of the University of Tel Aviv and the American Museum of Natural History discussing the secret lives — and deaths — of astronomers’ “standard candles” of universal distance, Type Ia supernovae.
Judging distances across intergalactic space isn’t easy, so in order to figure out how far away galaxies are astronomers have learned to use the light from Type Ia supernovae, which flare up with the brilliance of 5 billion Suns… and rather precisely so.
Type Ia supernovae are thought to be created from a pairing of two stars: one super-dense white dwarf which draws in material from a binary companion until a critical mass — about 40% more mass than the Sun – is reached. The overpacked white dwarf suddenly undergoes a rapid series of thermonuclear reactions and explodes in an incredibly bright outburst of material and energy.
But exactly what sorts of stellar pairs lead to Type Ia supernovae and how frequently they occur aren’t known, and that’s what Ph.D candidate Or Graur is aiming to learn more about.
“We don’t really know what kind of star it is that leads to these explosions, which is kind of embarrassing,” says Graur. “The companion star could be a regular star like our Sun, a red giant or supergiant, or another white dwarf.”
Because stars age at certain rates, by looking deeper into space with the Hubble and Subaru telescopes Graur hopes to determine how often and when in the Universe’s history Type Ia supernovae occur, and thus figure out what types of stars are most likely responsible.
“My rate measurements favor a second white dwarf as the binary companion,” Graur says, “but the issue is far from settled.”
Watch the video for the full story, and visit PHD TV and PHD Comics for more great science illustrations.
Video: PHDComics. Animation: Jorge Cham. Series Producer: Meg Rosenburg. Inset image: merging white dwarfs causing a Type Ia supernova. (NASA/CXC/M Weiss)
Part of a stereographic projection of Mercury’s north pole
Talk about northern exposure! This is a section of a much larger image, released today by the MESSENGER team, showing the heavily-cratered north pole of Mercury as seen by the MESSENGER spacecraft’s Mercury Dual Imaging System (MDIS) instrument.
See the full-size image below:
Many MDIS images were averaged together to create a mosaic of Mercury’s polar region, which this stereographic projection is centered on. MESSENGER is at its lowest altitude as it passes over Mercury’s northern hemisphere — about 200 kilometers (124 miles), which is just a little over half the altitude of the ISS.
The largest centrally-peaked crater near the center is Prokofiev, named after a 20th-century Russian composer. Approximately 110 km (68 mi.) in diameter, its permanently-shadowed interior is home to radar-bright deposits that are thought to contain water ice.
Even though Mercury is almost three times closer to the Sun than Earth is and hosts searing daytime temperatures of 425ºC (800ºF), there’s virtually no atmosphere to hold or transmit that heat. Nighttime temperatures can reach as low as -185ºC (-300ºF), and since a day on Mercury is 176 Earth days long it gets very cold for quite a long time!
Also, because Mercury’s axis of rotation isn’t tilted like Earth’s, low elevation areas near the poles receive literally no sunlight. Unless vaporized by a meteorite impact any ice gathered inside these deep craters would remain permanently frozen.
Here’s an orthographic projection of the image above, showing what the scene would look like on Mercury — that is, if it was ever fully lit by the Sun, which it isn’t.
Many of the craters on Mercury’s north pole have recently been named after famous artists, authors and composers, such as Kandinsky, Stieglitz, Goethe, and even one named after J.R.R. Tolkien. You can see an annotated image showing the names of Mercury’s north polar craters here.
On November 29, NASA will host a news conference at 2 p.m. EST to reveal new observations from MESSENGER, the first spacecraft to orbit Mercury. The news conference will be carried live on NASA Television and the agency’s website… you can tune in on NASA TV here.
Image credits: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Every year, Steve Cariddi releases the wonderful Year in Space Calendar, and the new edition for 2013 is even better, with amazing pictures, cool history and handy space facts for the upcoming year.
Seriously, this calendar is beautiful. There are more than 100 gorgeous photos of space, Moon phases for every day, daily space facts and historical references. And the calendar is huge, much larger than a traditional wall calendar.
Every month you’ll see:
– An in-depth exploration of human space flight, planetary exploration, or deep sky wonders
– Multiple images and detailed captions
– A mini-biography of famous astronomer, scientist, or astronaut related to the topic
– 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 graphically displayed
And thanks to the folks at Year in Space, we’ve got 5 copies of The Year in Space: 2013 Calendar to give away to Universe Today readers – a $12.95 value.
In order to be entered into the draw, just put your email address into the box below before Friday, November 30th, 2012. We’ll send you a confirmation email, so you’ll need to click that to be entered into the draw.
[giveaway]
We’re only going to use these email addresses for Universe Today giveaways/contests and announcements. We won’t be using them for any other purpose, and we definitely won’t be selling the addresses to anyone else. Once you’re on the giveaway notification list, you’ll be able to unsubscribe any time you like.
This great shot of the Milky Way includes some mysterious beams of light. But astrophotographer Peter Greig supplies the festive explanation: “This is a shot I took in Soisdorf, Germany earlier this year,” he writes. “The beams of light on the right are coming from a carnival in a nearby village!”
This photo was taken on September 7, 2012 using a Canon EOS 550D.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
This timelapse is different than most because it allows you to see the actions of the South African Large Telescope (SALT) from a unique point of view: the camera is mounted on the mirror structure, but also visible is the awesome field of view. Dr. Bruno Letarte compiled this video from 3 consecutive nights observing in July 2012 showing SALT in action. He also provides a tour of the inside of the telescope as well.
Additionally, Letarte provides detailed info of what is being observed, what scientist or team is doing the observing, and additional details of what is actually happening. If you want a more traditional timelapse of the night sky, see below for Letarte’s Volume I of this pair of videos. It shows a stunningly beautiful look at the southern sky, and points out several of the constellations and other objects that are visible. Continue reading “Timelapse From Inside a Telescope”
An online simulator for galactic collisions (Adrian Price-Whelan/Columbia University)
Have you ever had the desire to build your own galaxies, setting your own physical parameters and including as many stars as you want, and then smash them together like two toy cars on a track? Well, now you can do just that from the comfort of your own web browser (and no waiting billions of years for the results!)
This interactive online app by Adrian Price-Whelan lets you design a galaxy, including such parameters as star count, radius and dispersion rate, and then create a second galaxy to fling at it. Clicking and dragging on the black area will send the invading galaxy on its course, letting you watch the various results over and over again. (If those SMBH’s hit, look out!)
Inset image: Hubble interacting galaxies UGC 9618, 450 million light-years away. Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)
Back in October the partnering countries of the International Space Station announced an agreement to send two crew members to the International Space Station on a one-year mission designed to collect valuable scientific data needed to send humans to new destinations in the solar system. Today, NASA, the Russian Federal Space Agency (Roscosmos) announced they have selected the first crew to be part of such a mission: NASA has selected Scott Kelly and Roscosmos has chosen Mikhail Kornienko.
Kelly and Kornienko begin their mission in the spring of 2015, launching on Russian Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan in spring 2015 and will land in Kazakhstan in spring 2016. Kelly and Kornienko have trained together before, as Kelly was a backup crew member for the station’s Expedition 23/24 crews, where Kornienko served as a flight engineer.
“Congratulations to Scott and Mikhail on their selection for this important mission,” said William Gerstenmaier, associate administrator for Human Exploration and Operations at NASA Headquarters in Washington. “Their skills and previous experience aboard the space station align with the mission’s requirements. The one-year increment will expand the bounds of how we live and work in space and will increase our knowledge regarding the effects of microgravity on humans as we prepare for future missions beyond low-Earth orbit.”
NASA astronaut Scott Kelly
Kelly is the twin brother of former astronaut Mark Kelly, who is married to Gabrielle Giffords, the former US Congresswoman who was shot by an assailant in January of 2011.
The goal of their yearlong expedition is to understand better how the human body reacts and adapts to the harsh environment of space. Data from the 12-month expedition will help inform current assessments of crew performance and health and will determine better and validate countermeasures to reduce the risks associated with future exploration as NASA plans for missions around the moon, an asteroid and ultimately Mars.
“Selection of the candidate for the one year mission was thorough and difficult due to the number of suitable candidates from the Cosmonaut corps,” said head of Russian Federal Space Agency, Vladimir Popovkin. “We have chosen the most responsible, skilled and enthusiastic crew members to expand space exploration, and we have full confidence in them.”
Kelly, a captain in the U.S. Navy, is from Orange, N.J. He has degrees from the State University of New York Maritime College and the University of Tennessee, Knoxville. He served as a pilot on space shuttle mission STS-103 in 1999, commander on STS-118 in 2007, flight engineer on the International Space Station Expedition 25 in 2010 and commander of Expedition 26 in 2011. Kelly has logged more than 180 days in space.
Russian cosmonaut Mikhail Kornienko
Kornienko is from the Syzran, Kuibyshev region of Russia. He is a former paratrooper officer and graduated from the Moscow Aviation Institute as a specialist in airborne systems. He has worked in the space industry since 1986 when he worked at Rocket and Space Corporation-Energia as a spacewalk handbook specialist. He was selected as an Energia test cosmonaut candidate in 1998 and trained as an International Space Station Expedition 8 backup crew member. Kornienko served as a flight engineer on the station’s Expedition 23/24 crews in 2010 and has logged more than 176 days in space.
During the 12 years of permanent human presence aboard the International Space Station, scientists and researchers have gained valuable, and often surprising, data on the effects of microgravity on bone density, muscle mass, strength, vision and other aspects of human physiology. This yearlong stay will allow for greater analysis of these effects and trends.
Kelly and Kornienko will begin a two-year training program in the United States, Russia and other partner nations starting early next year.
Image Caption: Thanksgiving Greetings from Mars ! Curiosity snaps Head and Shoulders Self-Portrait on Sol 85 while posing at windblown ‘Rocknest’ ripple with eroded rim of Gale Crater in the background. This color mosaic was assembled from Mastcam 34 raw images snapped on Sol 85 (Nov. 1, 2012). See below the utterly cool animation of Curioity’s 1st ever ‘Touch and Go’ maneuver. Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/Marco Di Lorenzo
In the days leading up to Thanksgiving, NASA’s Curiosity mega Mars rover completed her first so-called “touch and go” maneuver – whereby she drives to and inspects an interesting rock and then moves on the same day to the next target of interest.
Check out the totally cool action animation below depicting Curiosity’s first ever “touch and go” movement and a subsequent martian drive of 83 feet (25.3 meters) conducted on Nov. 18.
“The ‘touch and go’ on Sol 102 went well, the data arriving in time for planning Sol 104”, says rover team member Ken Herkenhoff, of the US Geological Survey (USGS).
On Nov 16, Curiosity drove 6.2 feet (1.9 meters) to get within arm’s reach of a rock called “Rocknest 3”. She deployed the arm and placed the Alpha Particle X-Ray Spectrometer (APXS) instrument onto the rock, and then took two 10-minute APXS readings of data to ascertain the chemical elements in the rock.
Thereafter Curiosity stowed her 7 foot (2.1 m) long arm and drove eastward toward the next target called “Point Lake”.
Curiosity is now inside the ‘Glenelg’ geologic formation which the science team selected as the first major science destination because it lies at the intersection of three diverse types of geology areas that will help unlock the secrets of Mars’ ancient watery history and evolution to modern times.
Image Caption: Panoramic mosaic shows gorgeous Glenelg snapped by Curiosity on Sol 64 (Oct. 10) with eroded crater rim and base of Mount Sharp in the distance. Curiosity is now touring inside Glenelg. This is a cropped version of the full mosaic as assembled from 75 images acquired by the Mastcam 100 camera. Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/Marco Di Lorenzo
“We have done touches before, and we’ve done goes before, but this is our first ‘touch-and-go’ on the same day,” said Curiosity Mission Manager Michael Watkins of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “It is a good sign that the rover team is getting comfortable with more complex operational planning, which will serve us well in the weeks ahead.”
During the holiday period, Curiosity is taking high resolution imagery, conducting atmospheric observations and making measurements with the DAN neutron spectrometer and her other state-of-the-art science instruments.
Meanwhile, the Curiosity science team is still ‘chewing over’ the meaning of the results from the first ever scoopful of soil spooned up at ‘Rocknest’ and ingested by the SAM (Sample Analysis at Mars) chemistry instrument on the rover deck that is designed to detect organic molecules – the building blocks of life.
“We’ve got a briefing on Monday [Dec 3] where we’ll discuss our results,” Curiosity project manager John Grotzinger, of Caltech, told me. Those SAM results will be announced to a flurry of interest during the annual meeting of the AGU (American Geophysical Union) being held from Dec 3-7 in San Francisco.
Learn more about Curiosity’s groundbreaking discoveries, SAM and NASA missions at my upcoming pair of free presentations for the general public at two colleges in New Jersey:
Dec 6: Free Public lecture titled “Atlantis, The Premature End of America’s Shuttle Program and What’s Beyond for NASA” including Curiosity, Orion, SpaceX and more by Ken Kremer at Brookdale Community College/Monmouth Museum and STAR Astronomy club in Lincroft, NJ at 8 PM
Dec 11: Free Public lecture titled “Curiosity and the Search for Life on Mars (in 3 D)” and more by Ken Kremer at Princeton University and the Amateur Astronomers Association of Princeton (AAAP) in Princeton, NJ at 8 PM – Princeton U Campus at Peyton Hall, Astrophysics Dept.
The well-known star-forming region of the Orion Nebula. Credit: Canada-France-Hawaii Telescope / Coelum (J.-C. Cuillandre & G. Anselmi)
Precise distances are difficult to gauge in space, especially within the relatively local regions of the Galaxy. Stars which appear close together in the night sky may actually be separated by many hundreds or thousands of light-years, and since there’s only a limited amount of space here on Earth with which to determine distances using parallax, astronomers have to come up with other ways to figure out how far objects are, and what exactly is in front of or “behind” what.
Recently, astronomers using the 340-megapixel MegaCam on the Canada-France-Hawaii Telescope (CFHT) observed the star-forming region of the famous Orion nebula — located only about 1,500 light-years away — and determined that two massive groupings of the nebula’s stars are actually located in front of the cluster as completely separate structures… a finding that may ultimately force astronomers to rethink how the many benchmark stars located there had formed.
Although the Orion nebula is easily visible with the naked eye (as the hazy center “star” in Orion’s three-star sword, hanging perpendicular below his belt) its true nebulous nature wasn’t identified until 1610. As a vast and active star-forming region of bright dust and gas located a mere 1,500 light-years distant, the various stars within the Orion Nebula Cluster (ONC) has given astronomers invaluable benchmarks for research on many aspects of star formation.
Now, CFHT observations of the Orion nebula conducted by Dr. Hervé Bouy of the European Space Astronomy Centre (ESAC) and Centre for Astrobiology (CSIC) and Dr. João Alves of the Institut für Astronomie (University of Vienna) have shown that a massive cluster of stars known as NGC 1980 is actually in front of the nebula, and is an older group of approximately 2,000 stars that is separate from the stars found within the ONC… as well as more massive than once thought.
“It is hard to see how these new observations fit into any existing theoretical model of cluster formation, and that is exciting because it suggests we might be missing something fundamental.”
– Dr. João Alves, Institut für Astronomie, University of Vienna
In addition their observations with CFHT — which were combined with previous observations with ESA’s Herschel and XMM-Newton and NASA’s Spitzer and WISE — have led to the discovery of another smaller cluster, L1641W.
According to the team’s paper, “We find that there is a rich stellar population in front of the Orion A cloud, from B-stars to M-stars, with a distinct 1) spatial distribution; 2) luminosity function; and 3) velocity dispersion from the reddened population inside the Orion A cloud. The spatial distribution of this population peaks strongly around NGC 1980 (iota Ori) and is, in all likelihood, the extended stellar content of this poorly studied cluster.”
The findings show that what has been known as Orion Nebula Cluster is actually a combination of older and newer groups of stars, possibly calling for a “revision of most of the observables in the benchmark ONC region (e.g., ages, age spread, cluster size, mass function, disk frequency, etc.)”
“We must untangle these two mixed populations, star by star, if we are to understand the region, and star formation in clusters, and even the early stages of planet formation,” according to co-author Dr. Hervé Bouy.
The team’s article “Orion Revisited” was published in the November 2012 Astronomy & Astrophysics journal. Read the CFHT press release here.
The Canada-France-Hawaii Telescope’s Mauna Kea summit dome in September 2009. Credit: CFHT/Jean-Charles Cuillandre
Inset image: Orion nebula seen in optical – where the molecular cloud is invisible – and infrared, which shows the cloud. Any star detected in the optical in the line of sight over the region highlighted in the right panel must therefore be located in the foreground of the molecular cloud. Credit: J. Alves & H. Bouy.
An enormous tree-shaped prominence spreads its “branches” tens of thousands of miles above the Sun’s photosphere in this image, a section of a photo acquired in hydrogen alpha (Ha) by Alan Friedman last week from his backyard in Buffalo, NY.
Writes Alan on his blog, “gotta love a sunny day in November!”
Check out the full image — along with an idea of just how big this “tree” is — after the jump:
Taken through a special solar telescope and a Grasshopper CCD camera, Alan’s gorgeous solar photos show the Sun in a wavelength absorbed by atomic hydrogen — most present in the photosphere and chromosphere — thus revealing the complex and dynamic activity of the Sun’s “surface”.
Here’s the full image:
The dark circle at upper left (added by me) shows approximately the scale size of Earth (12,756 km, or about 7,926 miles diameter.) As you can see, that particular prominence is easily six times that in altitude, and spreads out many more times wider… and this isn’t even a particularly large prominence! As far as solar activity goes, this is a non-event. (Not like what was seen by SDO on Nov. 16!)
Regardless, it makes for an impressive backyard photo.
Check out more of Alan’s photos on his blog and on his website, AvertedImagination.com. Many of his photos, some of which have been shown at galleries across the U.S., are available as limited-edition prints. (Alan also runs a greeting card print studio.) I’ve found that he usually shares at least a couple of fantastic solar shots every month, if not more.
