Possible Bright Supernova Lights Up Spiral Galaxy M61

An animation showing a comparison between the confirmation image (at top) and an archive photo. Credit: Ernesto Guido, Martino Nicolini, Nick Howes

I sat straight up in my seat when I learned of the discovery of a possible new supernova in the bright Virgo galaxy M61. Since bright usually means close, this newly exploding star may soon become visible in smaller telescopes. It was discovered at magnitude +13.6 on October 29th by Koichi Itagaki of Japan, a prolific hunter of supernovae with 94 discoveries or co-discoveries to his credit. Itagaki used a CCD camera and 19.6-inch (0.50-m) reflector to spy the new star within one of the galaxy’s prominent spiral arms. Comparison with earlier photos showed no star at the position. Itagaki also nabbed not one but two earlier supernovae in M61 in December 2008 and November 2006.

The possible supernova in the bright galaxy M61 in Virgo is located 40" east and 7" south of the galaxy's core at right ascension (RA) 12 h 22', declination (Dec) +4º 28' It's currently magnitude +13.4 and visible in the morning sky before dawn in 8-inch and larger telescopes. Credit: Ernesto Guido, Martino Nicolini, Nick Howes
The possible supernova in the bright galaxy M61 in Virgo is located 40″ east and 7″ south of the galaxy’s core at right ascension (RA) 12 h 22′, declination (Dec) +4º 28′. It’s currently magnitude +13.4 and visible in the morning sky before dawn in 8-inch and larger telescopes. Credit: Ernesto Guido, Martino Nicolini, Nick Howes

Overnight, Ernesto Guido and crew used a remote telescope in New Mexico to confirm the new object. We’re still waiting for a spectrum to be absolutely sure this is the real deal and also to determine what type of explosion occurred. In the meantime, it may well brighten in the coming mornings.

M61 is a beautiful barred spiral galaxy located about 55 million light years from Earth in the constellation Virgo. It's one of the few galaxies to show spiral structure in smaller telescopes. Credit: Hunter Wilson
M61 is a beautiful barred spiral galaxy located about 55 million light years from Earth in the constellation Virgo. It’s one of the few galaxies to show spiral structure in smaller telescopes. Credit: Hunter Wilson

Supernovae are divided into two broad categories – Type Ia and Type II. In a Type Ia event,  a planet-sized white dwarf star in close orbit around a normal star siphons off matter from its companion which builds up on the surface of the dwarf until it reaches critical mass at which point the core ignites and consumes itself and the star in one titanic nuclear fusion reaction.  A cataclysmic explosion ensues as the star self-destructs in blaze of glory.

Evolution of a Type Ia supernova. Credit: NASA/ESA/A. Feild
Evolution of a Type Ia supernova. Credit: NASA/ESA/A. Feild

Type Ia explosions can become 5 billion times brighter than the Sun – the reason we can see them across so many light years – and eject matter into space at 5,000 – 20,000 km/second. Type II events mark the end of the life of a massive supergiant star. As these behemoths age, they burn by fusing heavier and heavier elements in their cores from hydrogen to carbon to silicon and finally, iron-nickel. Iron is inert and can’t be cooked or fused to create more energy. The star’s internal heat source, which has been staving back the force of gravity all these millions of years, shuts down.  Gravity takes hold with a vengeance, the star quickly collapses then rebounds in a titanic explosion. Ka-boom! 

Artist's impression of a Type II supernova explosion which involves the destruction of a massive supergiant star. Credit: ESO
Artist’s impression of a Type II supernova explosion which involves the destruction of a massive supergiant star. Credit: ESO

Like the Type Ia event, a Type II supernova grows to fantastic brilliance. Besides a legacy of radiant light, star debris, the creation of heavy elements like gold and lead, a Type II event will sometimes leave behind a tiny, city-sized, rapidly-spinning neutron star – the much compressed core of the original star – or even a black hole. So yes, life can continue for a giant star after a supernova event. But like seeing a former classmate at your 40th high school reunion, you’d hardly recognize it.

The "Y" or cup of Virgo rises into good view shortly before the start of dawn or about 2 hours before sunrise. This map shows the sky facing east around 6 a.m. local time (DST) and 5 a.m. starting Sunday when Daylight Saving Time is done. Source: Stellarium
The “Y” or “cup” of Virgo rises into good view shortly before the start of dawn or about 2 hours before sunrise. This map shows the sky facing east around 6 a.m. local time (DST) tomorrow October 31 and 5 a.m. standard time starting Sunday when Daylight Saving Time ends. Source: Stellarium

Are you itching to see this new supernova for yourself? Here are a couple maps to help you find it. M61 is located in the middle of the “Y” of Virgo not far from the familiar bright double star Gamma Virginis.  From many locations, the galaxy climbs to 15-20° altitude in the east-southeast sky just before the start of dawn, just high enough for a good view. Once you find the galaxy, look for a small “star” superimposed on its eastern spiral arm as shown in the photo at the top of this article.

In this close up view, stars are shown to magnitude +7.5. M61 is right between 16 and 17 Virginis (magnitudes 5 and 6.5 respectively). Source: Stellarium
In this close up view, stars are shown to magnitude +7.5. M61 is right between 16 and 17 Virginis (magnitudes 5 and 6.5 respectively). Click to enlarge.  Source: Stellarium

I’ll be out there with my scope watching and will report back once it’s established what type of supernova happens to be blowing up in our eyepieces. More information about the new object can be found anytime at David Bishop’s Latest Supernovae site. Good luck, clear skies!

** Update Nov. 1 : M61’s supernova now has a name and type! SN 2014dt is a Type Ia (exploding white dwarf) with some peculiarities in its spectrum. It’s also little brighter at magnitude +13.2.

What Does a Supernova Sounds Like?

What Does a Supernova Sounds Like?

We’ve all been ruined by science fiction, with their sound effects in space. But if you could watch a supernova detonate from a safe distance away, what would you hear?

Grab your pedantry tinfoil helmet and say the following in your best “Comic Book Guy” voice: “Don’t be ridiculous. Space does not have sound effects. You would not hear the Death Star exploding. That is wrong.” There are no sounds in space. You know that. Why did you even click on this?

Wait! I still have thing I want to teach you. Keep that tinfoil on and stick around. First, a quick review. Why are there sounds? What are these things we detect with our ear shell-flaps which adorn the sides of our hat-resting orb?

Sounds are pressure waves moving through a medium, like air, water or beer. Talking, explosions, and music push air molecules into other molecules. Through all that “stuff” pushing other “stuff” it eventually pushes the “stuff” that we call our eardrum, and that lets us hear a thing. So, much like how there’s not enough “stuff” in space to take a temperature reading. There’s not enough “stuff” in space to be considered a medium for sound to move through.

Don’t get me wrong there’s “stuff” there. There’s particles. Even in intergalactic depths there are a few hundred particles every cubic meter, and there’s much more in a galaxy. They’re so far apart though, the particles don’t immediately collide with each other allowing a sound wave to pass through a grouping of them.

So, even if you did watch the Death Star explode, you couldn’t hear it. This includes zapping lasers, and exploding rockets. Unless two astronauts touched helmets together, then they could talk. The sound pressure moves through the air molecules in one helmet, through the glass transferring from one helmet to the other, and then pushes against the air inside the helmet of the listening astronaut. Then they could talk, or possibly hear one another scream, or just make muffled noises under the face-hugger that had been hiding in their boot.

There’s no sound in space, so you can’t hear what a supernova sounds like. But if you’re willing to consider swapping out your listening meats for other more impressive cybernetic components, there are possibilities. Perhaps I could offer you something in a plasma detection instrument, and you could hear the Sun.

Artist's concept of NASA's Voyager spacecraft. Image credit: NASA/JPL-Caltech
Artist’s concept of NASA’s Voyager spacecraft. Image credit: NASA/JPL-Caltech

Voyager 1 detects waves of particles streaming from the Sun’s solar wind. It was able to hear when it left the heliosphere, the region where the Sun’s solar wind buffets against the interstellar medium.

Or you could try something in the Marconi Auralnator 2000 which is the latest in radio detector implants I just made up. If there was such a thing, you could hear the plasma waves in Earth’s radiation belts. Which would be pretty amazing, but perhaps somewhat impractical for other lifestyle purposes such as watching Ellen.

So, if you wanted to hear a supernova you’d need a different kind of ear. In fact, something that’s not really an ear at all. There are some exceptions out there. With dense clouds of gas and dust at the heart of a galaxy cluster, you could have a proper medium. NASA’s Chandra X-Ray Observatory has detected sound waves moving through these dust clouds. But you would need ears millions of billions of times more sensitive to hear them.

NASA and other space agencies work tirelessly to convert radio, plasma and other activity into a sound pressure format that we can actually hear. There are beautiful things happening space. I’ve included a few links below which will take you to a few of these, and they are really quite incredible.

Earthsong

Lightning on Saturn, Helium in the atmosphere, etc.

New Supernova Pops in Bright Galaxy M106 in the ‘Hunting Dogs’

The new Type II supernova is nestled up to the nucleus of the galaxy in this photo taken May 21 with a 17-inch telescope. Credit: Gianluca Masi, Francesca Nocentini and Patrick Schmeer

A supergiant star exploded 23.5 million years ago in one of the largest and brightest nearby galaxies. This spring we finally got the news. In April, the Katzman Automatic Imaging Telescope (KAIT) as part of the Lick Observatory Supernova Search, photographed a faint “new star” very close to the bright core of M106, a 9th magnitude galaxy in Canes Venatici the Hunting Dogs. 

The core of a red or blue supergiant moments before exploding as a supernova looks like an onion with multiple elements "burning" through the fusion process to create the heat to stay the force of gravity. Fusion stops at iron. With no energy pouring from the central core to keep the other elements cooking, the star collapses and the rebounding shock wave tears it apart.
The inner core of a red or blue supergiant moments before exploding as a supernova looks like an onion with multiple elements “burning” through the fusion process to create the heat and pressure that stays the force of gravity. Fusion stops at iron. With no energy pouring from the central core to keep the other elements cooking, the star collapses and the rebounding shock wave tears it apart.

A study of its light curve indicated a Type II supernova – the signature of a rare supergiant star ending its life in the most violent way imaginable. A typical supergiant star is 8 to 12 times more massive than the sun and burns at a much hotter temperature, rapidly using up its available fuel supply as it cooks lighter elements like hydrogen and helium into heavier elements within its core. Supergiant lifetimes are measured in the millions of years (10-100 million) compared to the frugal sun’s 11 billion years. When silicon fuses to create iron, a supergiant reaches the end of the line – iron can’t be fused or cooked into another heavier element – and its internal “furnace” shuts down. Gravity takes over and the whole works collapses in upon itself at speeds up to 45,000 miles per second.

When the outer layers reached the core, they crushed it into a dense ball of subatomic particles and send a powerful shock wave back towards the surface that rips the star to shreds. A supernova is born!  Newly-minted radioactive forms of elements like nickel and cobalt are created by the tremendous pressure and heat of the explosion. Their rapid decay into stable forms releases energy that contributes to the supernova’s light.

This Hubble Space Telescope image shows how spectacular M106 truly is. Its spiral arms are dotted with dark lanes of dust, young star clusters rich with hot, blue stars and tufts of pink nebulosity swaddling newborn stars. The galaxy is the 106th entry in the 18th century French astronomer Charles Messier's famous catalog. Credit: NASA / ESA
This Hubble Space Telescope image shows how spectacular M106 truly is. Dark filaments of dust are silhouetted against billions of unresolved suns. Young star clusters rich with hot, blue stars and tufts of pink nebulosity swaddling newborn stars ornament the galaxy’s spiral arms. A supermassive black hole rumbles at the heart of the galaxy. M106 is the 106th entry in Charles Messier’s famous catalog created in the 18th century. It’s located 23.5 million light years away. Credit: NASA / ESA

For two weeks, the supernova in M106 remained pinned at around magnitude +15, too faint to tease out from the galaxy’s bright, compact nucleus for most amateur telescopes. But a photograph taken by Gianluca Masi and team on May 21 indicate it may have brightened somewhat. They estimated its red magnitude – how bright it appears when photographed through a red filter – at +13.5. A spectrum made of the object reveals the ruby emission of hydrogen light, the telltale signature of a Type II supernova event.

At magnitude +9, M106 visible in almost any telescope and easy to find. Start just above the Bowl of the Big Dipper which stands high in the northwestern sky at nightfall in late May. The 5th magnitude stars 5 CVn (5 Canes Venatici) and 3 CVn lie near the galaxy. Star hop from the Bowl to these stars and then over to M106. Stars plotted to mag. +8. Click to enlarge. Stellarium
At magnitude +9, M106 visible in almost any telescope and easy to find. Start just above the Bowl of the Big Dipper which stands high in the northwestern sky at nightfall in late May. The 5th magnitude stars 5 CVn (5 Canes Venatici) and 3 CVn lie near the galaxy. Star hop from the Bowl to these stars and then over to M106. Stars plotted to mag. +8. Click to enlarge. Stellarium

Visually the supernova will appear fainter because our eyes are more sensitive to light in the middle of the rainbow spectrum (green-yellow) than the reds and purple that bracket either side. I made a tentative observation of the object last night using a 15-inch (37-cm) telescope and hope to see it more clearly tonight from a darker sky. We’ll keep you updated on our new visitor’s brightness as more observations and photographs come in. You can also check Dave Bishop’s Latest Supernovae site for more information and current images.

Even if the supernova never gets bright enough to see in your telescope, stop by M106 anyway. It’s big, easy to find and shows lots of interesting structure. Spanning 80,000 light years in diameter, M106 would be faintly visible with the naked eye were it as close as the Andromeda Galaxy. In smaller scopes the galaxy’s bright nucleus stands out in a mottled haze of pearly light; 8-inch(20-cm) and larger instrument reveal the two most prominent spiral arms. M106 is often passed up for the nearby more famous Whirlpool Galaxy (M51). Next time, take the detour. You won’t be disappointed.

 

Gallery: Incredible Mirages In Space Show Dark Matter, Supernovas And Galaxies

This artist’s impression of a supernova shows the layers of gas ejected prior to the final deathly explosion of a massive star. Credit: NASA/Swift/Skyworks Digital/Dana Berry

How can an exploding star appear far brighter than expected? This question vexed astronomers since the discovery of PS1-10afx, supernova that was about 30 times more luminous than other Type 1A supernovas. Astronomers have just confirmed in Science that it was likely due to well-known illusion in space.

The mirage is called a gravitational lens that happens when a huge object in the foreground (like a galaxy) bends the light of an object in the background. Astronomers use this trick all the time to spy on galaxies and even to map dark matter, the mysterious substance believed to make up most of the universe.

Check out some spectacular images below of the phenomenon in action.

Canada-France-Hawaii-Telescope (CFHT) image of the field before the supernova PS1-10afx. (Credit: Kavli IPMU / CFHT)
Canada-France-Hawaii-Telescope (CFHT) image of the field before the supernova PS1-10afx. (Credit: Kavli IPMU / CFHT)
Dark matter in the Bullet Cluster.  Otherwise invisible to telescopic views, the dark matter was mapped by observations of gravitational lensing of background galaxies. Credit: X-ray: NASA/CXC/CfA/ M.Markevitch et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/ D.Clowe et al. Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.;
Dark matter in the Bullet Cluster. Otherwise invisible to telescopic views, the dark matter was mapped by observations of gravitational lensing of background galaxies. Credit: X-ray: NASA/CXC/CfA/ M.Markevitch et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/ D.Clowe et al. Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.;
Hubble Space Telescope image shows Einstein ring of one of the SLACS gravitational lenses, with the lensed background galaxy enhanced in blue. A. Bolton (UH/IfA) for SLACS and NASA/ESA.
Hubble Space Telescope image shows Einstein ring of one of the SLACS gravitational lenses, with the lensed background galaxy enhanced in blue. A. Bolton (UH/IfA) for SLACS and NASA/ESA.
The image is made from HST data and shows the four lensed images of the dusty red quasar, connected by a gravitational arc of the quasar host galaxy. The lensing galaxy is seen in the centre, between the four lensed images. Credit: John McKean/HST Archive data
The image is made from HST data and shows the four lensed images of the dusty red quasar, connected by a gravitational arc of the quasar host galaxy. The lensing galaxy is seen in the centre, between the four lensed images. Credit: John McKean/HST Archive data
The HST WFPC2 image of gravitational lensing in the galaxy cluster Abell 2218, indicating the presence of large amount of dark matter (credit Andrew Fruchter at STScI).
The HST WFPC2 image of gravitational lensing in the galaxy cluster Abell 2218, indicating the presence of large amount of dark matter (credit Andrew Fruchter at STScI).
A picture of the object J1000+0221, which demonstrates the most distant gravitational lens ever discovered. This Hubble picture shows a normal galaxy's center region (the glow in the picture), but the object is also aligned with a younger, star-creating galaxy that is in behind. The object in the foreground pulls light from the background galaxy with gravity -- making rings of  pictures. Credit: NASA/ESA/A. van der Wel
A picture of the object J1000+0221, which demonstrates the most distant gravitational lens ever discovered. This Hubble picture shows a normal galaxy’s center region (the glow in the picture), but the object is also aligned with a younger, star-creating galaxy that is in behind. The object in the foreground pulls light from the background galaxy with gravity — making rings of pictures. Credit: NASA/ESA/A. van der Wel

Supernova Sweeps Away Rubbish In New Composite Image

The supernova remnant G352.7-0.1 in a composite image with X-rays from the Chandra X-Ray Telescope (blue), radio waves from the Very Large Array (pink), infrared information from the Spitzer Space Telescope (orange) and optical data from the Digital Sky Survey (white). Credit: X-ray: NASA/CXC/Morehead State Univ/T.Pannuti et al.; Optical: DSS; Infrared: NASA/JPL-Caltech; Radio: NRAO/VLA/Argentinian Institute of Radioastronomy/G.Dubner

Shining 24,000 light-years from Earth is an expanding leftover of a supernova that is doing a great cleanup job in its neighborhood. As this new composite image from NASA reveals, G352.7-0.1 (G352 for short) is more efficient than expected, picking up debris equivalent to about 45 times the mass of the Sun.

“A recent study suggests that, surprisingly, the X-ray emission in G352 is dominated by the hotter (about 30 million degrees Celsius) debris from the explosion, rather than cooler (about 2 million degrees) emission from surrounding material that has been swept up by the expanding shock wave,” the Chandra X-Ray Observatory’s website stated.

“This is curious because astronomers estimate that G352 exploded about 2,200 years ago, and supernova remnants of this age usually produce X-rays that are dominated by swept-up material. Scientists are still trying to come up with an explanation for this behavior.”

More information about G352 is available in the Astrophysical Journal and also in preprint version on Arxiv.

Source: Chandra X-Ray Telescope

SOFIA Gives Scientists a First-Class View of a Supernova

This Image of M82 including a supernova at near-infrared wavelengths J, H, and K (1.2, 1.65, and 2.2 microns), made Feb. 20 by the FLITECAM instrument on SOFIA. (NASA/SOFIA/FLITECAM team/S. Shenoy)

Astronomers wanting a closer look at the recent Type Ia supernova that erupted in M82 back in January are in luck. Thanks to NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) near-infrared observations have been made from 43,000 feet — 29,000 feet higher than some of the world’s loftiest ground-based telescopes.

(And, technically, that is closer to M82. If only just a little.)

All sarcasm aside, there really is a benefit from that extra 29,000 feet. Earth’s atmosphere absorbs a lot of wavelengths of the electromagnetic spectrum, especially in the infrared and sub-millimeter ranges. So in order to best see what’s going on in the Universe in these very active wavelengths, observational instruments have to be placed in very high, dry (and thus also very remote) locations, sent entirely out into space, or, in the case of SOFIA, mounted inside a modified 747 where they can simply be flown above 99% of the atmosphere’s absorptive water vapor.

NASA's airborne SOFIA observatory (SOFIA/USRA)
NASA’s airborne SOFIA observatory (SOFIA/USRA)

During a recent 10-hour flight over the Pacific, researchers aboard SOFIA turned their attention to SN2014J, one of the closest Type Ia “standard candle” supernovas that have ever been seen. It appeared suddenly in the relatively nearby Cigar Galaxy (M82) in mid-January and has since been an exciting target of observation for scientists and amateur skywatchers alike.

In addition to getting a bird’s-eye-view of a supernova, they used the opportunity to calibrate and test the FLITECAM (First Light Infrared Test Experiment CAMera) instrument, a near infrared camera with spectrographic capabilities mounted onto SOFIA’s 2.5-meter German-built main telescope.

What they’ve found are the light signatures of heavy metals being ejected by the exploding star. (Rock on, SN2014J.)

“When a Type Ia supernova explodes, the densest, hottest region within the core produces nickel 56,” said Howie Marion from the University of Texas at Austin, a co-investigator aboard the flight. “The radioactive decay of nickel-56 through cobalt-56 to iron-56 produces the light we are observing tonight. At this life phase of the supernova, about one month after we first saw the explosion, the H- and K-band spectra are dominated by lines of ionized cobalt. We plan to study the spectral features produced by these lines over a period of time and see how they change relative to each other. That will help us define the mass of the radioactive core of the supernova.”

Three images of M82 and the supernova SN2014J, including one from the FLITECAM instrument on SOFIA (right). Credit: NASA/SOFIA/FLITECAM team/S. Shenoy
Three images of M82 and the supernova SN2014J, including one from the FLITECAM instrument on SOFIA (right). Credit: NASA/SOFIA/FLITECAM team/S. Shenoy

Further observations from SOFIA will help researchers learn more about the evolution of Type Ia supernovas, which in addition to being part of the life cycles of certain binary-pair stars are also valuable tools used by astronomers to determine distances to far-off galaxies.

Researchers work at the FLITECAM instrument station on board SOFIA on Feb. 20 (NASA/SOFIA/N. Veronico)
Researchers work at the FLITECAM instrument station on board SOFIA on Feb. 20 (NASA/SOFIA/N. Veronico)

“To be able to observe the supernova without having to make assumptions about the absorption of the Earth’s atmosphere is great,” said Ian McLean, professor at UCLA and developer of FLITECAM. “You could make these observations from space as well, if there was a suitable infrared spectrograph to make those measurements, but right now there isn’t one. So this observation is something SOFIA can do that is absolutely unique and extremely valuable to the astronomical community.”

Read more in a SOFIA news article by Nicholas Veronico here.

Source: SOFIA Science Center, NASA Ames

UPDATE 4 March 2014: The FY 2015 budget request proposed by the White House will effectively shelf the SOFIA mission, redirecting its funding toward planetary missions like Cassini and an upcoming Europa mission. Unfortunately, SOFIA’s flying days are now numbered, unless German partner DLR increases its contribution. Read more here. 

How Supernova 2014J Will Help Determine the Extragalactic Distance Scale and Impact Cosmology

Comparison images from just before the supernova in M82 until Feb 7, 2014. Credit and copyright: Tom Wildoner.

In only three weeks since its discovery on January 21, 2014, much has been learned about the new supernova SN 2014J in Messier 82, the “Cigar” galaxy. In addition to early confirmation based on its spectrum that it is indeed a type Ia supernova, it is now understood to be the nearest type Ia explosion to our Milky Way galaxy since 1986.

Its unique proximity alone makes SN 2014J one the most important supernova ever observed. It will impact our understanding both of the type Ia-class of supernovae and of the Universe as a whole, because our Universe’s size, age, and ultimate fate are linked intimately to observations of type Ia supernovae, and because the precision with which they can be applied to estimate Universal-scale distances depends crucially on the nearest examples. SN 2014J is very likely to remain the nearest anchor-point in the type Ia supernovae-based distance scale for decades to come.

“Being the nearest supernova of this kind, SN 2014J will help us to better calibrate the expansion of the Universe,” said Adam Riess, co-leader of the Supernova H0 for Equation of State (SHOES) project, and co-winner of the 2011 Nobel Prize in Physics.

Observations of type Ia supernovae led to the discovery that our Universe is made mostly of dark energy, and that its expansion rate is apparently accelerating. That discovery earned the 2011 Nobel Prize in Physics for Riess, Saul Perlmutter, and Brian Schmidt.

Measuring ever more accurately our Universe’s exact expansion rate has been the Holy Grail of cosmology since Hubble’s discovery of expansion in 1929. Type Ia are perfect for probing cosmological scale distances, because these stellar explosions occur only when white dwarf stars exceed a certain critical mass, equivalent to 1.4 solar masses.

M82 with Supernova 2014J imaged on January 23, 2014. Credit and copyright: Anna Morris.
M82 with Supernova 2014J imaged on January 23, 2014. Credit and copyright: Anna Morris.

As a result, most type Ia supernova explode with roughly the same intrinsic or absolute magnitude. They therefore provide a unique kind of “standard candle,” by which any type Ia supernova observed to be one hundred times fainter than another can be understood to be exactly ten times farther than the other. In practice, subtle differences between actual type Ia supernovae, amounting to around ten percent on average in their net effect on distance estimates, are accounted for. Technically, therefore, type Ia supernova provide “standardizable candles.”

Normal type Ia supernovae are well understood. Within just days of its discovery, Robert Quimby of the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo was able to predict the peak apparent magnitude of m_V = 10.5 and time of peak brightness of February 2 for SN 2014J, more than a week prior to their occurrence. As observations now available show, as summarized in the light-curve available thanks to the American Association of Variable Star Observers, Quimby’s prediction based on the light-curves of other similar type Ia supernova, was spot on (see Figure 1, below).

Light curves for SN 2014J and SN 2011fe, the next nearest type Ia supernova, show blue magnitudes are ~1.3 mag fainter (blue dots) than visual magnitudes (green dots) for SN 2014J, due to obscuring dust in host galaxy Messier 82, compared to the normal, non-obscured, and nearly over-lapping blue and visual magnitudes for SN 2011fe. Courtesy of the American Association of Variable Star Observers.
Light curves for SN 2014J and SN 2011fe, the next nearest type Ia supernova, show blue magnitudes are ~1.3 mag fainter (blue dots) than visual magnitudes (green dots) for SN 2014J, due to obscuring dust in host galaxy Messier 82, compared to the normal, non-obscured, and nearly over-lapping blue and visual magnitudes for SN 2011fe. Courtesy of the American Association of Variable Star Observers.

While SN 2014J is a normal type Ia supernova, its light-curve reveals it is highly reddened, as in dimmed and obscured by large amounts of dust present and intervening in its host galaxy. The amount of reddening is indicated by the difference between the blue and visual magnitudes. Known as extinction, measured as E = (B-V), for SN 2014J the extinction amounts to ~1.3 mag. That compares to the next nearest recent type Ia supernova, SN 2011fe in galaxy Messier 101, at 23 million light-years (7.0 Megaparsecs). It’s light-curve shows SN 2011fe was reddened very little in comparison, i.e.- both spectrum and colour are normal.

The date of SN 2014J explosion’s first light has now been established to be January 14.72 UT, around one week prior to discovery January 21. That was reported in one of at least two papers already published online regarding SN 2014J, the one by WeiKang Zheng et al., and which has already been submitted to Astrophysical Journal Letters (see e-print here). SN 2014J is one of only four type Ia supernova with observations as early as one day after first light, the others including SN 2011fe mentioned, and SN 2009ig in galaxy NGC 1015 at 130 million light-years (41 Megaparsecs), and SN 2013dy in galaxy NGC 7250 at 46 million light-years (14 Megaparsecs).

Two rivals for nearest recent type Ia supernovae, SN 1972E in galaxy NGC 5253 and SN 1986G in NGC 5128, the Centaurus A galaxy, were cited early. Neither however, are argued to be directly relevant to the current distance scale zero point because neither have modern, complete, multi-band and multi-epoch observations including pre-maximum observations, which are quintessential to defining zero point type Ia supernovae, and data that is now being gathered for SN 2014J. For example, SN 2002fk in galaxy NGC 1309 at 100 million light-years (31 Megaparsecs) is one of only eight type Ia supernovae employed as zero point calibrators, because of their complete, multi-epoch, multi-band light-curve data, as employed for example by Riess et al. (see: 2011ApJ…730..119R).

In terms of which recent type Ia supernova was relatively nearest, the distances to the galaxies involved can be estimated based on analyzing essentially all of the redshift-independent distance estimates that have been published for galaxies since 1980, meaning in the modern era using CCDs and including observations based on NASA’s Hubble Space Telescope. Such galaxy distance estimates are tabulated in the NASA/IPAC Extragalactic Database of galaxy Distances (NED-D).

Galaxy Messier 82, the host of SN 2014J, is located at 12.0 million light-years (3.6 Megaparsecs), based on the mean of three kinds of distance indicator employing 8 different estimates. The standard deviation among those indicators is ~10%.

Galaxy NGC 5128, the host of SN 1986G, is also located at 12.0 million light-years, based on 11 different indicators employing 46 different distance estimates, and also with a standard deviation among indicators of ~10%. So, to within the precision of the indicators, both supernova occurred at essentially the same distance, confirming SN 2014J is the nearest since SN 1986G. Galaxy NGC 5253, the host of SN 1972E, is actually the nearest galaxy, at 11.0 million light-years (3.4 Megaparsecs) known to have hosted a type Ia supernova in the modern era, based on 6 indicators with 48 estimates.

M82 and Supernova 2014J imaged on January 23, 2014. Credit and copyright: Mick Hyde.
M82 and Supernova 2014J imaged on January 23, 2014. Credit and copyright: Mick Hyde.

Accounting for its dimming due to the dust in Messier 82 is just one part of several involved in applying data from SN 2014J to estimate its distance. Future observations of its declining magnitude will reveal its complete light-curve. That will enable estimates to be made of its decline time and light-curve stretch factors. Once these are in hand, within the next few to several weeks at most, SN 2014J will begin its use as the nearest type Ia supernova anchor point.

More of a milestone than a Rosetta stone, SN 2014J will nevertheless have an impact of lasting legacy on future applications of type Ia supernova observations in cosmology. It will be especially significant to enhancing the use of type Ia supernova as cosmological distance indicators. That is important to ongoing projects, including the SHOES project, the Carnegie Hubble Program, and others, all of which aim to measure the Universe’s expansion rate or Hubble constant to an accuracy of better than one percent within the next decade. That level of accuracy is required in order to understand not only our Universe’s exact size and age, but also the exact Equation-of-State governing our Universe’s total energy, including its dark energy.

Webcast: “Stellar Explosions and Death Dances”

When stars die, their final gasps can trigger the most powerful blasts of energy in the universe. Their demise can also lead to a bizarre death dance as the voracious corpse of a dead star begins consuming a nearby companion.

Today (Feb. 5) you can watch a live webcast (or watch the replay later) to learn about the recent detection of a dying star igniting the most powerful blast ever seen – something so powerful it radiated energy that was nearly 50 billion times that of visible light. Also learn how scientists have discovered that a familiar sight in the skies is actually our earliest view yet of a star being consumed by the remnant of a nearby exploded star.

The webcast starts at 19:00 UTC (3 pm EDT, Noon PDT). You can watch below. To submit questions ahead of time or during the webcast, send an email to [email protected] or post on Twitter with hashtag #KavliLive. You can find additional information from the Kavli Foundation here.

More Great Images of Supernova 2014J Plus View it During Live Webcasts

M82 and Supernova 2014J imaged on January 23, 2014. Credit and copyright: Mick Hyde.

Images keep pouring in of the biggest excitement in astronomy this week, a new Type Ia supernova in the Cigar Galaxy, 82, about 12 million light years away. As has been said, the Cigar got lit!

This is the closest supernova of this type since the 1800’s. Astrophotographers have been out in full force trying to nab this event, we’ve got more great images to share today, and we’ll keep adding them as they come in.

If you haven’t been able to take a look for yourself, you can join a live webcast from the folks at the Virtual Telescope Project on Saturday, January 25, 2014 at 20:30 UTC (3 pm EST, 1 pm PST), which you can watch here.

Plus, Fraser and the Virtual Star Party will surely try to nab M82 during their hangout on Sunday January 26 at 9 pm EST. Click the VSP link to find out when it starts in your time zone.

SN2014J on January 23, 2014, as seen from Rhode Island. Credit and copyright: Lloyd Merrill
SN2014J on January 23, 2014, as seen from Rhode Island. Credit and copyright: Lloyd Merrill
M82 with Supernova 2014J imaged on January 23, 2014. Credit and copyright: Anna Morris.
M82 with Supernova 2014J imaged on January 23, 2014. Credit and copyright: Anna Morris.
M82 and SN2014J as seen through a 6 inch telescope on January 23, 2014. Credit and copyright: Bill Magee.
M82 and SN2014J as seen through a 6 inch telescope on January 23, 2014. Credit and copyright: Bill Magee.
Before and after the supernova in M82. Credit and copyright: Astrokid96 on Flickr.
M82 and M81 imaged on January 23, 2014. Credit and copyright: Gregory Hogan.
M82 and M81 imaged on January 23, 2014. Credit and copyright: Gregory Hogan.
Comparison images of M82 nine months apart: on April 4, 2013 and January 23, 2014. Credit and copyright: Paul Campbell.

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