M101 supernova update

By Phil Plait | August 25, 2011 6:03 pm

Images are starting to come in already of the new supernova in the nearby spiral galaxy M 101. Here’s a color image of the exploding star from the Faulkes North telescope on — wait for it — Haleakala:

[Click to embiggen.]

That’s color and very pretty, but I think this one is more impressive, showing the supernova gaining in brightness by a factor of six in a single day:

[Again, click to endeflagrate.]

That’s taken by the Palomar 48 inch telescope in California. The images show M 101 on August 22, 23, and 24. You can see (or not see in this case) how it wasn’t there on the first night, shows up on the second, and is now much brighter. It will get brighter yet, and may get into range of visibility using good binoculars! Certainly even a small telescope will be able to see this supernova once it reaches maximum brightness, which won’t happen for at least a week, if not more.

Right now, the Moon is a waning crescent, so it won’t be a problem for 10 days or so. If you have a telescope and a camera, get out there!

Credits: BJ Fulton, LCOGT; Peter Nugent and the Palomar Transient Factory

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: M 101, supernova

Comments (53)

  1. I’m waiting for my 2600mm camera lens to be delivered. Might not enough for this exactly but I’m as excited as a child on Christmas eve. The moon photo’s I’m going to get!

    How big a telescope do you reckon you’d need to see this at all?

  2. Randy Owens

    I’m pondering just how much time Phil spends each day coming up with new ways to say “embiggen”. “Endeflagrate”???

    Edit to add:
    @1FL: According to the Berkeley article Phil linked to earlier, it should be visible through binoculars at its peak (with dark skies), so pretty much any telescope should do.

  3. Jason

    This is very cool. This will be studied for years I am sure. I hope you learn a lot and we can use to refine some of those big questions about supernova

  4. Jason

    A 2600mm lens? Pardon me while I drool. Hope you have one checks a tripod or other mount. What is the f-stop on that thing? 5.6?

  5. Brandon

    Boy, I couldn’t have picked a better weekend for going to a dark sky preserve. I’m hoping this sucker is at least a magnitude 11 or so by Saturday; with no moon and a dark sky, I might be able to get it in my 110mm telescope.

  6. Awesome news. Great images. Thanks. :-)

    Shame it’s so far in the Northern hemisphere I won’t be able to observe it myself. :-(

    PS. the link seems to have an issue though – clicking it I ends up at your ‘So it goes: Kurt Vonnegut, 1922 – 2007’ post from April 11th, 2007 9:56 PM instead.

    PPS. Click on my name for M101’s wiki-page if folks are curious to know more galaxy~wise. :-)

  7. AAAAAAARRRRRGGGHHHHHH!!! im at -33° 9′ latitude, snif!
    y lpm que lo recontramil tiró, we are about to get the BVRI filters for the 16″ telescope. It would have been nice to do photometry for the first time with this…

  8. Any word yet on whether any neutrinos got detected above the background level? Obviously there wasn’t a Gold alert since the Supernova Early Warning System didn’t send out an email, but it is still possible that one of the big detectors saw a spike. I think that SNO is not up right now, so that leaves IceCube and Super-K as the two possibilities. My minimal knowledge base suggests that Borexino and LVD would definitely not be sensitive enough at this distance. This seems farther than the standard distance that Super-K and IceCube are generally discussed for. The most obvious problem with IceCube aside from distance would be that IceCube can only detect stuff from the Northern Hemisphere but M101 is ok for that. Me want neutrinos!

  9. Justin B

    Do we know if this Supernova will generate a black hole?

  10. Laurence


    I was under the impression that galactic things take thousands of years. But your saying this star blew up by a factor of 6 in a day? That’s crazy!

  11. According to the caption in http://www.ia.ucsb.edu/pa/display.aspx?pkey=2550 the color image was taken by another LCOGT telescope located in California.

  12. Digital Atheist

    Wouldn’t “emdetonate” or “emexplodenate” be a bit more accurate? I got a feeling that thing throwing stuff out a bit past supersonic speeds. 😉

  13. It should be noted that the “Faulkes Telescope” is a big telescope bought, substantially refurbished, and placed into public service by the Las Cumbres Observatories organization out of Santa Barbara. Wayne Rosing is the benefactor and main creative force behind LCO. http://lcogt.net/ They have a movie on the SNe there http://bit.ly/ppJNnJ

  14. Jay

    I could be wrong but it is my understanding that you need a Type II Supernova to create a black hole and this is with a star would leave a core of about 3 solar masses or more that would collapse into a black hole. A type Ia Supernova is caused by a white dwarf (a star like our Sun that has gone through its red giant stage and shed its outer layers) that steals matter from a companion star (binary system at least) until it reaches 1.38 solar masses or the Chandrasekhar limit when the star basically exceeds the electron degeneracy pressure that maintains it, collapses and then is unbound.

    My guess is that this SN will take a couple of weeks to really brighten and visual observers should then have a treat before it gets too low in the sky to see. One problem not mentioned if your a visual observer is M101 is best seen in a telescope at a dark sky site and not in the backyard of most urban homes. We’ve had quite a treat so far and especially this summer with one SN in M51 and now one in M101. SN summer of the Messier galaxies.

  15. @ ^ Jay & #9. Justin B :

    Jay is correct – a white dwarf type Ia supernovae leaves behind nothing but an expanding shell of material – the star(s*) involved get totally and utterly destroyed leaving no core remnant.

    Type Ib,c, & II supernovae produced by supermassive stars leave behind neutron stars (of various flavours incl. magnetars & perhaps quark stars or strange stars) and black holes which gets produced depending on the mass of the star at the core. Most will produce neutron stars lacking cores over the 2 – 3 solar mass Tolman–Oppenheimer–Volkoff limit to result in black holes. Those that have cores with masses above twice solar end up imploding wth such force that even neutrons can’t hold them up and out of ultimate collapse into a singularity.

    Although pair-instability supernovae produced by the most massive hypergiants and Population III “stellar first born” are so explosive they too destroy their progenitor satrs entirely.

    Click on my name for the supernovae wikipage if that helps.


    * Depending on which method of exploding a white dwarf occurs. One theory has it that type Ia SN are caused by white dwarfs accreting matter from a nearby companion star such as a red giant while another suggests they are the result of mergers between two white dwarfs. Perhaps both these causes occur & result in supernovae too.

  16. nico

    Is there an obvious reason why the center of the galaxy appears significantly brighter in the image on the right? Wouldn’t whichever technical change makes the center brighten in that last image also affect the brightness of the supernova, thus reducing the comparability of the images?

  17. Jeff

    Had a fun couple of hours with my 12-yr-old daughter tonight, trying to find M101 with binoculars and my Galileoscope at 25x. I don’t really know what I’m doing but it was still enjoyable. Should I be able to see M101? Is it going to be a disc or a point? I found the right place, roughly, with the binoculars but will have to try again tomorrow with the Galileoscope. Sometimes the maps I have don’t really correspond well to the sky because one is flat and the other curved, so it is hard to trace a straight line to find what I want. Anyway it was still fun! If nothing else I can technically treat tonight as the “before” if the supernova does become visible with one of these devices after a few days…

  18. Wouldn’t “emdetonate” or “emexplodenate” be a bit more accurate? I got a feeling that thing throwing stuff out a bit past supersonic speeds. 😉

  19. Other Paul


    “emdetonate” or “emexplodenate”?

    Now you’ve done it. I now have to know if there’s such a thing as a subnova (or a superveta).

  20. FC

    The closest I’ve been to seeing another galaxy other than the Milky Way is a small smudge of Andromeda through binos. It looked like one of those gamma correction tests on monitors :-(

  21. Scott Hurst

    I’m with 18/FC.

    Actually, I can just barely tell there is a dim cotton ball of fuzz where m101 should be in 10×50 binos and in a little 100mm refractor. It’s the kind of thing where I can see it unti I look at it directly and then it vanishes.

    On the other hand, tomorrow is *the* dark Saturday of the month. I’m planning about a 2 hour drive West of Ft Worth to get my nearest patch of (nearly) pristine sky (per the Dark Sky Finder page). But this dry hot weather and many random grass fires all over the state make for some pretty terrible haze.

  22. Pete Jackson

    Best thing now is for you folks with telescopes to get them out tonight and draw the field surrounding M101 including all the stars you can see. Then when the SN gets bright enough, you will be able to immediately pick it out.

  23. Anon

    Why does it take so long for these things to brighten up? If they’re explosions, shouldn’t they get to their max brightness almost immediately?

  24. DennyMo

    BA, glad you got to say “Haleakala” without having to preface it with “Holy”. :)

    21. Anon Says: “Why does it take so long for these things to brighten up? If they’re explosions, shouldn’t they get to their max brightness almost immediately?”

    Partly because the thing that’s exploding is HUGE. If you’ve ever watched slow-motion video of an earthly explosion, figure out how long it takes material to travel the short distance you see. Then ramp that up to stellar scale. As celestial events go, novae (novas? whatever) are *very* immediate.

    I’m a little confused on where to find it in the night sky. Near the Big Dipper, got that much. Is it *in* the spot marked M101 on this chart, or *near* it?

  25. Anon, there are a variety of issues going on. In some types of supernova the outer layers are heavily ionized at first so they are less transparent to light. Ionization is reduced allowing more light through. This is relevant for some types of Type II supernova but not this.

    Another thing is that supernova produce some heavy elements. A lot of the light is due to the residual decay of heavy elements. Some of those have long decay chains with the first part of the chain producing a lot less radiation. So it takes time for those isotopes to decay into stuff that produces a lot of radiation. This occurs in this type of supernova with Nickel-56 which decays into Cobalt 56. There are some complicating factors (a lot of the radiation goes to just heat the surrounding gas so we will see that hot gas rather than the radiation from the isotopes) but that’s the basic idea.

  26. XRBfan

    @16 nico, I had the same thought. The difference is probably due to weather. A thin cloud would make it fainter. However, when you see numbers like “6 times brighter” it was compared against another standard star in the frame, so the effect of weather is removed.

    @23 Anon, the optical emission is largely from the shock wave of the blast running into the interstellar medium, not from the explosion itself. It takes a few days for it to reach the dust and gas to light it up. The initial boom produces X-rays (or sometimes gamma rays in SN Ic) almost immediately which fade quickly.

  27. @17 Jeff:
    M101 is a face-on spiral that, while it might have a high apparent magnitude, it has very low surface brightness. That is, it’s 7.8 apparent magnitude is spread across a large area making it appear much dimmer than it actually is.

    Through the Galileoscope, you might be able to detect the core of the galaxy, but it will look more like a fuzzy star than a galaxy. It would probably take something like 10X70 binoculars in order to pick up any hint of the galaxy’s disk.

  28. Anon

    @24-26: thanks for the explanation. It’d been bugging me for quite a while now – glad to finally have an answer to the question.

  29. Jon Hanford

    I’m really waiting to see hi-res imagery on this nearby event from the likes of Hubble, Chandra or the GBT showing the growth and expansion of the SNR over time. Light echoes may be detectable too. This really is one of the brightest nearby supernovae since SN 1987A in the LMC 24 years ago.

    I’ll have to take a look with my modest 4.25″ reflector (and 10×50 binos too!), weather permitting.

  30. @ Dennymo:

    I’m a little confused on where to find it in the night sky. Near the Big Dipper, got that much. Is it *in* the spot marked M101 on this chart, or *near* it?

    Your better star atlases generally show galaxies as oval shapes that roughly correspond to the size of the actual object. As M101 appears as a fairly featureless round haze with a slightly brighter center (and maybe a hint of the spiral arms) in most small to medium telescopes, it’s a fair bet this supernova will be quite easy to pick out.

    None of the photos I’ve seen so far indicate which direction is “up,” but it probably won’t matter. If you see the faint fuzzy glow of the galaxy, the brightest star just within it toward one edge will be this sucker.

  31. Duncan Kitchin

    unfortunately I’m pretty sure M101 is obscured by a tree in my back yard. It’s just possible that I get a view as it grazes the Western edge of the tree, though; once it’s fully dark here I’ll take a look and see if I can get an image…

  32. Duncan Kitchin


    I’m a little confused on where to find it in the night sky. Near the Big Dipper, got that much. Is it *in* the spot marked M101 on this chart, or *near* it?

    It’s in one of the spiral arms. Given the scale of the star chart you linked, it would be inside the circle for M101 as shown. I’d expect it to be extremely difficult to see visually.

  33. Awesome! I got lucky with the tree… M101 is *just* visible . I have my setup capturing images right now.

    Since I’m in my heavily light-polluted back yard, I’m using a hydrogen-alpha filter, which I haven’t used on a galaxy before, so I really have no idea how well it will work. I’ll post an image if the supernova turns out to be identifiable.

  34. Joseph G

    @12 Digital Atheist: My thoughts exctly. But then, I have no idea what the speed of sound is in the core of a massive star :)

  35. Duncan Kitchin

    Got it!

    Only managed to get a single 10 minute exposure. It disappeared back behind the tree again :(.

    That, together with the fact that it’s an H-alpha filtered image means it’s not exactly terrific quality, but it’s definitely there. I happened to have an older M101 image for comparison, and I checked against the Palomar images for location. It’s marked in the image:


  36. @ Duncan:

    Cool! Were you able to see it visually through your scope, or just on the 10 minute exposure?

    I’m facing the same situation with trees. Damn Ents!

    BTW…nice pix on your site! Love the shots of the planetary nebulas.

  37. Duncan Kitchin


    Thanks! No, I didn’t get to see it visually. I have the camera semi-permanently attached to that scope, and I’ve never put an eyepiece in it. In fact, I don’t own the necessary “ocular adapter” for it :)

  38. astronomynut

    Was able to see the supernova visually through both my scope and a smaller 14.5″ from a semi-dark site on 8/26. No site in Indiana is truly dark. Even with my 17.5″ the core of the galaxy was about all the detail M101 had to offer, but the SN had brightened enough to see it visually.

  39. smijer

    Howzabout another update long about now?

  40. Spoons

    I’m in badly-light-polluted central Connecticut, so M101 is a real struggle for me. I know WHERE it is (I feel like I’ve memorized the star hop from Alcor/Mizar by now), but have only seen maybe a vaguely fuzzy galaxy core and maybe an arm once. Literally, a year I’ve been looking for it with my Celestar 8. Have never gone inside and felt, “Yes, that was definitely it.”

    In a perverse way, was hoping for a power outage because of Irene and the dark moon. Didn’t get one at my house, but a lot of nearby areas are out. Went out last evening (the 29th) in my backyard with my scope and my new Canon 15×50 image-stabilized binocs.

    Just as an aside, the image-stabilized binocs are, in a word, awesome. I’ll end up using them more than my scope, I think. Save your money and buy some. They. Are. Magic.

    So, anyway, found M101 easily in the binocs the first try. Clearly a fuzzy “thing” near where it is supposed to be. So that was really exciting. First time I could definitely say that I saw it.

    Put the scope on it, and, god, it’s still so hard to see. Got a faint arm, a faint core. Honestly, if I didn’t know that was it, I would have just passed right by it.

    Using this great blog post:

    I very easily found the Supernova. Very cool. Even if you can’t see M101, the Supernova should be a piece of cake to see.

  41. Tom H

    I’ve started to get light curve data on the SN, with images taken on 8-29 and 9-1 local evening in Michigan. In those three nights the SN has doubled in brightness. I intend to follow it as long as local skies and altitude of M101 permit.

  42. AAVSO now have it at Mag 10.5

  43. PatM

    I was at the Merritt BC Star Quest ( http://www.merrittastronomical.com/ ) and had a look at M101 through my 12″ Skywatcher goto dob using a MallinCam Hyper Plus and the supernova was more than apparent on August 31. The previous clear night was Aug 27 and we didn’t see much with just visual viewing. Even with no light pollution and a 12″ reflector M101 wasn’t much more than a faint fuzzy. Like a dolt I forgot to capture a frame of video for it. I got 27, 51, 57 and a few others but forgot to snap the supernova…

  44. Milt

    I think ‘Bad Astronomy’ is a great title. I also think that some well meaning people have contributed to bad astronomy by telling the press that everyone should go out and look for this supernova. Some few will actually go look, and they are likely to be disappointed.

  45. Mark

    4, Jason, I have a 1300mm lens. It came with a doubler to 2600mm. At 1300, mine has an f stop of 16. At 2600 it’s 32. I also have another doubler I use (5200mm) to photograph the moon (Great Pics), but it leaves me with an f stop of 64. It has a 95mm polarizer that comes with it. Don’t know about you, but I love this lens.

  46. @47. Mark

    What kind of tripod do you use Mark? I have what I had previously believed to be a ‘sturdy’ tripod but with my new lens I have come to realise that… it might just be bloody useless! Well, almost.

    At maximum zoom it’s nigh on impossible to keep the camera steady and even the shutter action moves the setup significantly.

    So my questions are: what’s a good tripod for big lenses and are there any reasonably priced motorised mounts for camera’s specifically for astronomical photography?

  47. I made a step-by-step video on YouTube to help people “star hop” their way to the supernova from Mizar/Alcor. Hopefully it can help some people find their way to it more easily:


  48. Kelly G.

    Can you still see the M-101 in the night sky?


  49. Gordon Hommes

    I was able to observe the supernova in M101 from the Lake Superior Highlands north of Two Harbors, Minnesota, last night with a 4.25″ reflector. The supernova was clearly visible, seemingly superimposed on the irregular smudge of M101. The star appeared to be about 10th magnitude. M101 was only about 30 degrees above the horizon, so fortunately, the skies were dark and transparent.


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