BA: AstroAlert: Type Ia supernova in M101! (SN 2011fe)

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BA: AstroAlert: Type Ia supernova in M101! (SN 2011fe)

Post by bystander » Thu Aug 25, 2011 9:24 pm

AstroAlert: Type Ia supernova in M101!
Discover Blogs | Bad Astronomy | 2011 Aug 25
Attention all astronomers! There is a new Type Ia supernova that has been seen in the nearby spiral galaxy M101, and it’s very young — currently only about a day old! This is very exciting news; getting as much data on this event as possible is critical.

Most likely professional astronomers are already aware of the supernova, since observations have already been taken by Swift (no X-rays have yet been seen, but it’s early yet) and Hubble observations have been scheduled. Still, I would urge amateur astronomers to take careful observations of the galaxy.

[As an aside, I'll note that this supernova won't get bright enough to see naked eye and poses no threat at all to us here on Earth. It may be visible in decent-sized telescopes, though, and as you'll see this may be a very important event in the annals of astronomy.]

So why is this a big deal?

First of all, a supernova is an exploding star — one of the most violent events in the Universe. There are different kinds of supernovae, but a Type Ia occurs, it’s thought, when a superdense white dwarf — the remnant core of a dead star — siphons material off a companion star. If enough material piles on top of the white dwarf, it can suddenly start to fuse hydrogen into helium. This starts a runaway effect, and the entire star explodes. This supernova can release so much energy it can actually outshine its host galaxy! If you want more details, I’ve written about Type Ia supernovae before: Astronomers spot ticking supernova time bomb and Dwarf merging makes for an explosive combo.

So this kind of supernova is incredibly bright, making them easy to spot over vast distances. These events are very important, because we think that each Type Ia supernova is very similar in the way it explodes, making them useful as benchmarks in gauging distances to very distant galaxies. In fact, it is the study of these explosions that has helped us nail down how fast the Universe is expanding, and also led to the discovery of dark energy. Clearly, the more we know about them, the better.

M101 is a spiral galaxy only about 25 million light years away, making it one of the closest big spirals in the sky. It’s also huge, boasting a trillions stars, ten times the mass of our Milky Way. You can read all about it in an earlier post featuring the image at the top of this article.

Given M101′s close distance, this new supernova will be relatively easy to study. And the best part is that the exploding star was caught young: most of the ones we see are far away, and too faint to be seen until they start to reach their maximum brightness after a few days. Getting data on them early is absolutely critical for understanding them, and it’s the hardest part of all this. I am not exaggerating to say this new supernova could be a linchpin in our understanding of these events.

Interestingly, Hubble took images of this galaxy in 2002, and astronomers dug up the archived images and looked at the spot of the supernova to see if anything was there back then. Nothing shows up in the blue filter, but in the red (shown here) there are two stars very close to the position of the future supernova (the circle is centered on the best measurement of the supernova’s position). From their brightness and color, both of these stars are red giants, stars like the Sun but near the ends of their lives. That would fit with the Type Ia supernova: red giants are so big that if there’s a white dwarf nearby, it could suck up their matter and start the chain of events that led to its doom. Further observations may pin this down. If one of these stars is what fed the supernova, that’s seriously cool; there are only a handful of supernova progenitor stars that have ever been seen*.

All in all, this is pretty much a big deal. The galaxy is close, pretty, a bit odd, and is hosting the nearest Type Ia supernova seen in decades which was caught when it was less than a day old. I’m excited! I know a lot of telescopes will be aimed at the northern skies over the next few days, and I’ll be very interested to find out what they see.

Nearest supernova of its type in 40 years, say scientists
University of Oxford | 2011 Aug 25
Astronomers last night discovered a bright supernova, otherwise known as an exploding star, and say it is the nearest of its type observed for 40 years.

The supernova was spotted in the Pinwheel Galaxy, M101, a spiral galaxy a mere 21 million light years away, lying in the famous constellation of the Great Bear (Ursa Major).

Scientists from the University of Oxford made the discovery with their colleagues from the Palomar Transient Factory (PTF) collaboration, using a robotic telescope in California in the United States.

Oxford team leader, Dr Mark Sullivan, said: 'The most exciting thing is that this is what's known as a type 1a supernova - the kind we use to measure the expansion of the Universe. Seeing one explode so close by allows us to study these events in unprecedented detail.'

The supernova, dubbed PTF11kly, is still getting brighter, and the team's best guess is that it might even be visible with good binoculars in ten days' time, appearing brighter than any other supernova of its type in the last 40 years.

Dr Sullivan said; 'The best time to see this exploding star will be just after evening twilight in the Northern hemisphere in a week or so's time. You'll need dark skies and a good pair of binoculars, although a small telescope would be even better.'

Following the discovery, which was made at 8pm UK time last night, astronomers around the world were scrambled to get follow up images and data. Among the first to respond, within 90 minutes, was the robotic 2m Liverpool Telescope, located in the Canary Islands.

The team will be watching carefully over the next few weeks, and hope to use NASA's Hubble Space Telescope to study the supernova's chemistry and physics.The scientists in PTF have discovered more than 1,000 supernovae since it started operating in 2008, but they believe this could be their most significant discovery yet. The last time a supernova of this sort occurred so close was in 1972.

'Before that, you'd have to go back to 1937, 1898, and 1572 to find more nearby Type 1a supernovae,' said Professor Peter Nugent, from the Lawrence Berkeley National Laboratory in the USA. 'Observing PTF 11kly unfold should be a wild ride. It is an instant cosmic classic.'

The Palomar Transient Factory is a wide-field survey operated at the Palomar Observatory by the California Institute of Technology on behalf of a worldwide consortium of partner institutions. Collaborating institutions are Caltech, Columbia University, Las Cumbres Observatory Global Telescope, Lawrence Berkeley National Laboratory, UC Berkeley, University of Oxford, and the Weizmann Institute of Science (Israel).

Berkeley Scientists Discover an “Instant Cosmic Classic” Supernova
Lawrence Berkeley National Laboratory | 2011 Aug 25
Supercomputing, fast networks key to early discovery of explosion
A supernova discovered yesterday is closer to Earth — approximately 21 million light-years away — than any other of its kind in a generation. Astronomers believe they caught the supernova within hours of its explosion, a rare feat made possible with a specialized survey telescope and state-of-the-art computational tools.

The finding of such a supernova so early and so close has energized the astronomical community as they are scrambling to observe it with as many telescopes as possible, including the Hubble Space Telescope.

Joshua Bloom, assistant professor of astronomy at the University of California, Berkeley, called it “the supernova of a generation.” Astronomers at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, who made the discovery predict that it will be a target for research for the next decade, making it one of the most-studied supernova in history.

The supernova, dubbed PTF 11kly, occurred in the Pinwheel Galaxy, located in the “Big Dipper,” otherwise known as the Ursa Major constellation. It was discovered by the Palomar Transient Factory (PTF) survey, which is designed to observe and uncover astronomical events as they happen.

“We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,” said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova. Nugent is also an adjunct professor of astronomy at UC Berkeley. “Observing PTF 11kly unfold should be a wild ride. It is an instant cosmic classic.”

He credits supercomputers at the National Energy Research Scientific Computing Center (NERSC), a Department of Energy supercomputing center at Berkeley Lab, as well as high-speed networks with uncovering this rare event in the nick of time.

The PTF survey uses a robotic telescope mounted on the 48-inch Samuel Oschin Telescope at Palomar Observatory in Southern California to scan the sky nightly. As soon as the observations are taken, the data travels more than 400 miles to NERSC via the National Science Foundation’s High Performance Wireless Research and Education Network and DOE’s Energy Sciences Network (ESnet). At NERSC, computers running machine learning algorithms in the Real-time Transient Detection Pipeline scan through the data and identify events to follow up on. Within hours of identifying PTF 11kly, this automated system sent the coordinates to telescopes around the world for follow-up observations.

Three hours after the automated PTF pipeline identified this supernova candidate, telescopes in the Canary Islands (Spain) had captured unique “light signatures,” or spectra, of the event. Twelve hours later, his team had observed the event with a suite of telescopes including the Lick Observatory (California), and Keck Observatory (Hawaii) had determined the supernova belongs to a special category, called Type Ia. Nugent notes that this is the earliest spectrum ever taken of a Type Ia supernova.

“Type Ia supernova are the kind we use to measure the expansion of the Universe. Seeing one explode so close by allows us to study these events in unprecedented detail,” said Mark Sullivan, the Oxford University team leader who was among the first to follow up on this detection.

“We still do not know for sure what causes such explosions,” said Weidong Li, senior scientist at UC Berkeley and collaborator of Nugent. “We are using images from the Hubble Space Telescope, taken fortuitously years before an explosion to search for clues to the event’s origin.”

The team will be watching carefully over the next few weeks, and an urgent request to NASA yesterday means the Hubble Space Telescope will begin studying the supernova’s chemistry and physics this weekend.

Catching supernovae so early allows a rare glimpse at the outer layers of the supernova, which contain hints about what kind of star exploded. “When you catch them this early, mixed in with the explosion you can actually see unburned bits from star that exploded! It is remarkable,” said Andrew Howell of UC Santa Barbara/Las Cumbres Global Telescope Network. “We are finding new clues to solving the mystery of the origin of these supernovae that has perplexed us for 70 years. Despite looking at thousands of supernovae, I’ve never seen anything like this before.”

“The ability to process all of this data in near real-time and share our results with collaborators around the globe through the Science Gateway at NERSC is an invaluable tool for following up on supernova events,” says Nugent. “We wouldn’t have been able to detect and observe this candidate as soon as we did without the resources at NERSC.”

At a mere 21 million light-years from Earth, a relatively small distance by astronomical standards, the supernova is still getting brighter, and might even be visible with good binoculars in ten days’ time, appearing brighter than any other supernova of its type in the last 30 years.

“The best time to see this exploding star will be just after evening twilight in the Northern hemisphere in a week or so,” said Oxford’s Sullivan. “You’ll need dark skies and a good pair of binoculars, although a small telescope would be even better.”

The scientists in the PTF have discovered more than 1,000 supernovae since it started operating in 2008, but they believe this could be their most significant discovery yet. The last time a supernova of this sort occurred so close was in 1986, but Nugent notes that this one was peculiar and heavily obscured by dust.

”Before that, you’d have to go back to 1972, 1937 and 1572 to find more nearby Type Ia supernovae,” says Nugent.

'Once in a Generation' Supernova Discovered
University of California, Santa Barbara | 2011 Aug 25

Shiny and New Supernova Spotted in Nearby Galaxy
Universe Today | Jason Major | 2011 Aug 25

Possible Type-Ia Supernova in M101
Universe Today | Tammy Plotner | 2011 Aug 25

Supernova Erupts in Pinwheel Galaxy
Sky & Telescope | Kelly Beatty | 2011 Aug 25

M101 supernova update
Discover Blogs | Bad Astronomy | 2011 Aug 25

Closest Supernova in 25 Years Is a 'Cosmic Classic'
Space/com | 2011 Aug 26

Exploding star coming to a telescope near you
New Scientist | David Shiga | 2011 Aug 26

Uncovering the Secrets of the Great Supernova
W. M. Keck Observatory | 2011 Aug 26

APOD: A Young Supernova in the Nearby Pinwheel Galaxy (2011 Aug 26)
http://asterisk.apod.com/viewtopic.php?f=9&t=25056
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Beyond » Thu Aug 25, 2011 10:01 pm

Bad Astronomy's photo dosen't have the event circled in the photo as the written part says.
Berkeley's three photo's are the best.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by bystander » Thu Aug 25, 2011 10:18 pm

Beyond wrote:Bad Astronomy's photo dosen't have the event circled in the photo as the written part says.
Sorry, missed that link.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Beyond » Fri Aug 26, 2011 1:51 am

bystander wrote: Sorry, missed that link.
That's ok. After viewing it, you didn't miss much. Berkley's three are still the best.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Fri Aug 26, 2011 7:10 am

Wow, this is exciting.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by bystander » Fri Aug 26, 2011 7:26 am

Beyond wrote:That's ok. After viewing it, you didn't miss much. Berkley's three are still the best.
Actually, that link is from Berkeley, UC Berkeley.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Beyond » Fri Aug 26, 2011 11:20 am

Really?? Compared to the other two sets of photos, i never would have guessed. The last set of three is still the best, IMO, that is.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Mon Aug 29, 2011 5:04 am

Hmm, the picture doesn't seem to be loading. Well, check it out here yourself, then: http://www.universetoday.com/88465/astr ... k-johnson/

This appears to be one of the latest images of the supernova in M101. The picture is interesting because the supernova doesn't seem to have brightened much, at least to my untrained eyes. More interesting to me is the relatively non-blue color of the supernova. Admittedly it is very hard to make a color assessment from just one image of an astrophotographer whose "personal color balance" you are not familiar with. So it could be that the supernova is bluer than it appears to be here. But if not, I'm feeling a bit doubtful that it is a supernova type Ia in the first place.

Of course I may be very wrong about that, but, like I said, this supernova doesn't strike me as very typically Ia-ish.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by bystander » Mon Aug 29, 2011 5:54 am

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Mon Aug 29, 2011 5:03 pm

I realize, of course, that the chance that this supernova isn't a type Ia just because it doesn't seem to be the right color to me is exceedingly slim. But I look forward to news about the development of this supernova! Is it brightening the way it should, assuming that it is a type Ia supernova?

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Tue Aug 30, 2011 8:38 am

I found this on the net:
http://www.astronomerstelegram.org/?read=3594 wrote on 26 Aug 2011; 07:15 UT:

Continued Swift/UVOT Monitoring of PTF11kly / SN2011fe

The UV-Optical Telescope on Swift has continued to monitor the field of PTF11kly / SN2011fe (ATEL #3581). In an orbit beginning at 00:01:40 UT on 2011 August 26, we report the following preliminary AB magnitudes:

V: 13.83 +/- 0.03
B: 13.99 +/- 0.03
U: 15.26 +/- 0.03
UVW1: 17.33 +/- 0.05
UVM2: 18.92 +/- 0.08
UVW2: 18.48 +/- 0.07


Compared with the first epoch of UVOT imaging (ATEL #3590), the supernova has brightened significantly in all filters. The fastest evolution is occurring in the optical bands, implying the supernova is becoming redder with time.
So the supernova is brightening and becoming redder at the same time. At least I was right that the supernova is not remarkably blue any more.
Near Infrared Spectrum of SN Ia 2011fe Resembles Fast Decliners Observed A Week Before Maximum

We observed SN 2011fe with the IRTF 3.0m and the SpeX instrument on August 26.3. The spectrum reveals strong absorption features from MgII at 13500 km/s. The CaII infrared triplet forms a strong and broad feature with a minimum at about 22000 km/s. SiII and OI are also detected at about 12500 km/s. The presence of evolved MgII features in this NIR spectrum is suggestive of a phase no more than one week before maximum light. This estimate is different than about two weeks pre-maximum which would be inferred for this observation date from ATEL 3581. The strong MgII features are also indicative of SN Ia with fast decline rates: delta_m15 > 1.3. If SN 2011fe has a fast rise and fast decline, these observations will be closer to the maximum which is consistent with both aspects of the NIR spectrum. We thank John Rayner for making IRTF time available and Eric Volquardsen for help with the observations.
The supernova may not be brightening all that much more. I may be wrong, but my impression is that this supernova isn't particularly bright as supernovae type Ia go.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Tue Aug 30, 2011 4:50 pm

I can't let go of this supernova, because it bugged me that it turned out to be the wrong color.

As you could see in my last post, there is some evidence that SN2011fe may be a fast-decline supernova. If that is true, what does that mean for its maximum brightness?
http://astronomy.swin.edu.au/cms/astro/ ... ght+Curves wrote:

The maximum B-band luminosity is linked to how fast the light curve declines in the 15 days following B maximum ( Δm15 ). Brighter supernovae decline more slowly, and fainter supernovae decline more rapidly. This is known as the luminosity-decline rate relation right:. Astronomers use this relation to determine how over or underluminous a supernova is from a standard supernova before calculating its distance.
It is my opinion that SN2011fe is remarkably non-blue for a young supernova type Ia. It may be a fast decliner, especially in blue light. But as you can see from the quote above, a fast declining supernova type Ia is an underluminous one.

What a pity! Not only for me, who would of course have loved seeing a bright blue "new star" decorate the disk of the Pinwheel Galaxy. But it's a pity for science too, I think. Supernovae type Ia are useful for science precisely because they are so bright, as well as being standard candles. The way I understand it, astronomers know underluminous supernovae well enough to be able to determine the absolute luminosity of these "duds", too. Of course they aren't really duds, because they are still bright enough to be seen from very far away. However, when it comes to determine the force of dark energy, I really think that they are not as useful as the bright blue supernovae.
Image
To get an idea of what I think of as "normal" supernovae type Ia, take a look at this picture by NASA's Swift Telescope: :arrow:

The galaxy is called MCG +05-43-16, and it contains two supernovae. Supernova 2007ck (left) is a Type II event, and Supernova 2007co (right) is a Type Ia event. You can see that the type Ia supernove is much brighter and bluer than the type II one, though it helps that the type Ia one is two weeks younger than the type II one. When the picture was taken, the type Ia supernova was three weeks old. Therefore it was two weeks older when it was photographed than SN2011fe is today. SN2011fe was discovered on August 24 or 25, 2011, and today is August 30, 2011. The supernova in M101 is barely a week old.



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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Tue Aug 30, 2011 5:48 pm

One more post. Please.
Image
This is supernova SN 1998aq in galaxy NGC 3982. A. Saha, National Optical Astronomy Observatories, Allan Sandage, The Observatories of the Carnegie Institution of Washington, G. A. Tammann, Astronomisches Institut der Universität Basel, A. E. Dolphin and J. Christensen, National Optical Astronomy Observatories, and N. Panagia and F. D. Macchetto, Space Telescope Science Institute, wrote in their paper Cepheid Calibration of the Peak Brightness of Type Ia Supernovae. XI. SN 1998aq in NGC 3982 about SN 1998aq that its absolute V magnitude could be assumed to be between -19.67 ± 0.15 and -19.43 ± 0.15. The lower luminosity corresponds to zero reddening, which is of course quite unlikely.

The B-V index of 1998aq was reported to be -0.17 six days before B maximum. -0.17 is very blue indeed. However, another color measurement six days before B maximum yielded a very different color index, 0.02. According to the paper by Saha, Sandage et al., the normal intrincsic color of a supernova type Ia is -0.013.


We may note that according to the monitoring by Swift/UVOT, the current SN2011fe in M101 had the following colors on August 26, one or two days after discovery: V: 13.83 +/- 0.03, B: 13.99 +/- 0.03. This corresponds to a B-V index somewhere between 0.1 and 0.2, which is very red indeed compared with -0.17 for SN1998aq. It is even considerably redder than 0.02.

SN 2011fe is red. That is all there is to it. My guess is that it will turn out to be faint, too.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Wed Aug 31, 2011 9:07 am

Well, I've taken it upon myself to be a sort of watchdog of Supernova 2011fe, so...
Image

This photo of M101 and SN 2011fe was taken by Joseph Brimacombe on August 28. The supernova actually looks quite blue here. It is the bluest single object in the image.


The supernova may be brightening on schedule, too. Astro Bob wrote on August 29, only two days ago, that the Pinwheel galaxy supernova is headed for the record books - by that he meant that it is one of the apparently brightest supernovae ever seen in another galaxy.






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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Wed Aug 31, 2011 12:40 pm

According to http://www.rochesterastronomy.org/supernova.html, updated 08/31/2011 05:08:39, the magnitude of SN 2011fe is now 11.4.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Wed Aug 31, 2011 4:34 pm

On page http://www.skyandtelescope.com/observin ... 30288.html, Kelly Beatty wrote:
Updates:

The supernova was up to magnitude 13.8 on the American evening of the 25th, 13.2 on the evening of the 26th, and 12.4 on the evening of the 27th. By the evening of the 29th it was up to 11.5 and easier to spot than the galaxy itself in moderately light-polluted skies. On the evening of the 30th, S&T's Tony Flanders put it at 11.2.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Beyond » Wed Aug 31, 2011 11:16 pm

We need new pictures, or a series showing the brightness changes.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by bystander » Thu Sep 01, 2011 1:55 am

Beyond wrote:We need new pictures, or a series showing the brightness changes.
Go get us some. This guy will tell you how to find it.
Click to play embedded YouTube video.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Beyond » Thu Sep 01, 2011 3:05 am

:lol: I make a simple statement and i get told where to go. At least i can find the place, i know how to get a handle on it anyway, and i could even use my 100 power cheap binoculars to see it, if it's not cloudy or anything. But it's just a tad too far to get pictures of with my A490 pocket camera. Oh well, two out of three isn't to bad. Perhaps Berkley will make a little video of it, sometime after it hits it's peak brightness this weekend, or later, after it's brightness disappears, or stabilizes at a lower level.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Thu Sep 01, 2011 9:14 am

The latest update (09/01/2011 05:00:02) at http://www.rochesterastronomy.org/supernova.html, says that SN 2011fe is at magnitude 11.3.

The supernova may possibly have stopped brightening. Predictions were that the supernova would keep rising until September 9 or 10. If it is about to peak at around September 1 or 2, then SN 2011fe may indeed be a fast declining supernova.

But that remains to be seen.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Fri Sep 02, 2011 5:41 am

The supernova is still rising. http://www.rochesterastronomy.org/supernova.html, updated on Fri, 02 Sep 2011 03:36:16 GMT, puts the magnitdue of SN 2011fe at 11.0.

There are still very few images of the supernova. This one may be one of the latest, from August 29.

I found this list of images of SN 2011 and the people producing the images at rochesterastronomy.org.









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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Sat Sep 03, 2011 6:25 am

According to http://www.rochesterastronomy.org/supernova.html, updated on Sat, 03 Sep 2011 01:26:55 GMT, SN 2011fe does not seem to have brightened since yesterday. It holds at magnitude 11.0, the same as yesterday.

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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by neufer » Sat Sep 03, 2011 11:40 am

Image
Ann wrote:
SN 2011fe is red.

That is all there is to it.

My guess is that it will turn out to be faint, too.
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Sun Sep 04, 2011 5:31 am

Wow! The supernova has jumped! On Sun, 04 Sep 2011 04:22:15 GMT, http://www.rochesterastronomy.org/supernova.html put SN 2011fe at 10.5!
Image
I wonder why the supernova seemed to stall yesterday and then jump again. Judging from these idealized light curves of supernovae type Ia, it shouldn't do that. Could it be that, if SN 2011fe is redder than most supernovae of type Ia, this one is reddened by nearby dust clouds, and maybe yesterday the radiation from the supernova hit a dust cloud between it and us and made that dust cloud brighten?



Ann
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Ann
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Re: BA: AstroAlert: Type Ia supernova in M101!

Post by Ann » Mon Sep 05, 2011 12:38 am

SN 2011fe has been at magnitude 10.5 two days in a row now. http://www.rochesterastronomy.org/supernova.html, updated on Mon, 05 Sep 2011 00:14:40 GMT, puts the supernova at 10.5.

It has been at 10.5 two days in a row now, and before that it was at 11.0 two days in a row. Has it stalled? Tomorrow will tell!

Ann
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