Fireworks and pinwheels

By Phil Plait | February 8, 2006 2:08 pm

Sometimes NASA gets it right, of course. Despite the foofooraw about political censorship inside of NASA, very fine work gets done by the agency.

For example, that picture is from Hubble, launched by NASA in 1990 (click it for a bigger version, or here for a ginormous version). The galaxy is NGC 1309, a gorgeous face-on spiral roughly 100 million light years away. Oddly enough, astronomers consider that nearby.

That’s important, actually. There’s some real science behind this pretty face! About three years ago, the light from an exploding star in that galaxy reached our telescopes here on Earth. It was designated SN2002fk, meaning it’s a supernova, it blew up in 2002, and it was the 162nd one to be seen that year — they are labeled alphabetically, so the first was 2002a, the second 2002b, the 27th 2002aa, etc. But more than that, it’s a special type of supernova… the kind many astronomers like best.

It’s called a Type Ia, which means it was a binary star, a normal star like the Sun orbiting (or orbited by, depending on your taste) a white dwarf, a compact, very dense cinder of a star that was once like the Sun. It has intense gravity, which can draw matter off the other star which piles up on the surface of the dwarf. When the dwarf reaches a certain mass, suddenly the gravity is strong enough that the very matter which makes up the star can fuse catastrophically, turning the star into a gigantic hydrogen bomb. It’s a bit more powerful than your standard H-bomb, though: about 25 octillion (25,000,000,000,000,000,000,000,000,000) times a 1 megaton bomb.

The beauty of this type of supernova is that each one blows up with just about the same energy, meaning that any time you see one, in principle you can determine its distance! You just measure how bright it looks through the telescope and compare it to how bright you know it really is, and the distance just falls out of the equation. Presto!

Well, it’s not that easy, of course. We haven’t studied enough Type Ias to get a really good calibration on them. So when one appears in a nearby galaxy, like, say, NGC 1309, astronomers pounce on it. It’s bright, so they can get good data on it, and dissect it as much as possible.

Why? Well, the explosions are so bright they can be seen from large distances, even billions of light years. If you see one blow up, and you can figure out its distance, you can use them to measure things like how fast the Universe is expanding (it’s a bit like measuring distant car headlights at night to better understand the road you’re on). In fact, these are the very kind of supernovae used to figure out the universal expansion is accelerating! Astronomers are very keen to understand this better; it’s not exaggerating to say it’s one of the biggest problems in cosmology right now.

So when you look at that picture and admire its sheer beauty, let the thought rumble around in your mind that one of those tiny dots in the image is actually light from one of the fiercest events in the Universe, and may shine a light — literally — on the fate of the cosmos in which we live.’

CATEGORIZED UNDER: Astronomy, Cool stuff, Science

Comments (26)

  1. 25 octillion (25,000,000,000,000,000,000,000,000,000) times a 1 megaton bomb.

    Mythbusters, eat your hearts out….

  2. Nice. The fact that we can look back in time and see objects as they appeared over a million years ago always gives me chills. Such far-away objects are also proof against the young-Universe idea.

  3. BB


    This star blew up 100 million years ago, not in 2002

  4. jess tauber

    HOW DARE YOU INSULT THE CREATOR OF THE UNIVERSE BY REPRODUCING A GRAVEN IMAGE OF ONE OF HIS CREATIONS! It is clear to me that you must have your head cut and your eyes put out, in that order. After that you will be silenced! You have offended us, and so we will kill you. If you resist our vengeance, we will kill you again! All of your blog entries will be killed, and later censored!

    It is obvious that if Man were meant to see into the Heavens, the Creator would have put high-aperture telescopes into his head instead of eyes! So-called Dark Matter is invisible because the Creator wants it that way- WOE UNTO YOU for attempting to characterize it. And it is clear that accelerating expansion of the Universe is its attempt to avoid your blasphemous prying eyes!

    AND SO WE WARN YOU- you must stop this immediately, or the Committee for the Protection of Ancient Unexamined, Unexaminable, and Unquestionable Received Viewpoints (CPAUUURV), as the only legitimate recognized authority to whom one may appeal, MUST TAKE EXCESSIVELY DISPROPORTIONATE RETALIATORY ACTION!

    Governments of the world have recognized the need for moderation, conciliation, and compromise. YOU MUST COMPROMISE BY SUBMITTING UTTERLY! We will send you a new administration-sanctioned overseer immediately, who will instruct your children (if any) in the proper way.

    YOU SHOULD BE SLEEPING instead of staying up at night, against the NATURAL ORDER!

    THINK ON THIS BEFORE IT IS TOO LATE- we give you only 45 billion years to respond…….

    With Fondest Hopes of Your Redemption
    (at least in polite company!)

  5. So, if I understand correctly, the things nearer to us are red shifted a little more than they ought to be based on how fast it appears things far away are red shifted. My question: what does the expansion curve look like? Not that I’d actually understand the math for any longer than it takes to explain it.


  6. I wonder how the astrologists will spin(no pun intended) the effects of a new galaxy full of planets and stars on our lives here on earth. I wonder if I will meet an interesting stranger tomorrow or will the supernova cause me to have a conflict at work. I would love to get your take on my post on what astrologers had to say about the recently discovered new planet( I just found your blog and have enjoyed it greatly. I also learned a lot from your book as well. Mostly I learned that I didn’t know much about astronomy.

  7. Ahhh…back to the business of why I visit this blog to begin with; fine science. A refreshing break indeed from all of the kerfuffery of the last few days.

  8. Tara Mobley

    And we’re back to business. The absolute beauty of the cosmos, and the science that shows that it’s not just pretty, it’s fascinating too. It’s nice to see it again.

  9. RobW

    25 octillion Megatons…

    WOW, Just Wow.

    That’s big…

  10. wooooooo¡¡¡¡¡¡¡¡¡¡¡¡

    The universe is beutiful everywhere as soon as I turn my head.

  11. @Thomas Siefert: I’d rather NOT have the Mythbuster prove that (in)correct. Just let them fiddle around with the usual garden variety earth physics. Letting them fiddle with a ‘ginormous’ H-bomb… No thank you! 😉

  12. Kevin from NYC

    “you must have your head cut and your eyes put out, in that order.”

    That is so totally incorrect. You must first put out the eyes and then cut the head off…..idiot!

  13. jess tauber

    AHA! Kevin from NYC does not know! WE HAVE REVERSED THE CHARGES and so time goes other way! You are so electroweak. WE are MAGNETOSTRONG, and have monopoly on concept. Dirac is our Prophet. We have used 4th family fermions and super double secret probation 3/2 spin fundamental particles to reach out to you from hidden base inside supermassive black hole in Seyfert Galaxy! WE FIRE DWARF GALAXY AT YOU stupid people in “Milky Way” to force you pay attention but you don’t listen!

    We feed you gas at hyperinflationary price, hope you stop taking from everyone. BUT THEN YOU GO STEAL ALL RED DWARFS from smaller neighbors! HAVE YOU NO BRANES AT ALL?

    Not to worry- soon you will all be Hubbled!


  14. About Type 1a supernovae: do they create the heavy elements like other supernovae (Type 1b? Type 2?)?

  15. Phil, thanks for this clear and profound post.
    Another one for my archives.

    You are like the Port wine – the original, the portuguese one, not the one you try to produce/fake in California…:)
    As you get older, you get better!

    Jess Tauber … my magnificent supreme being, thanks for making me laugh
    like hell. Please, have mercy on us… as we don´t know what we are doing.

  16. supercorgi

    Absolutely beautiful. Such things raise a sense of awe in my completely atheistic, non-spiritual, black, little heart. How could people think that understanding the universe and how it works is detrimental to an appreciation of beauty? Oh, and thanks for the great new wallpaper for my computer screen!

  17. Cindy

    The same image is on today’s Astronomy Picture of the Day website. It’s really cool.

    When I was in grad school I studied cataclysmic variables (which is the binary systems that produce Type Ia supernovae) and felt that it was a very unsexy topic compared to supernovae and cosmology. I called it “granny nightgown” science. Glad to see that the cataclysmic variables are becoming a little more sexy now so we can better understand the Type Ia supernovae.

  18. TJ

    Well put ‘corgi! It was my grandfather giving me my first telescope that got me interested in astronomy, but it’s photos like this that keep me enraptured by it.

    I see something like this and immediately start subdividing the galaxy into sections, solar systems, planets, moons…then I wonder: How many of these stars have planets? How many have life? Intelligent life? What form is it? Do they resemble us or are they completely different?

    Is there someone looking at our galaxy and wondering the same thing?

    It’s so fun to think about!

  19. hey, snap! i studied CVs too. And, to my supervisor’s woe, also found them terminally boring. This was made even worse by the fact that my supervisor was Brian Warner, who literally wrote the book on the subject. Maybe it was the pressure, but now that i’ve graduated and i don’t do astronomy anymore, it just seems so much more fun! I can look at something like this and go ‘Neat!’ instead of ‘Hmm, am I going to get quizzed on this at tea tomorrow?’

  20. Nigel Depledge

    Thanks, BA, for another superb pic. And some staggeringly big numbers to go with it.

  21. Laguna2

    Thank you for my new Desktop background.
    That pic is beautiful.

  22. Gavin Flower


    I was wondering if anyone competent in astrophysics here (or relevant disciplines) has had a critical look at Alexander Mayer’s ideas about “Gravitational Transverse Redshift” and the implication that the red shift of distant galaxies therefore do not imply a “Big Bang”.

    I have looked at his two pdf files of lecture notes – his ideas appear reasonable to me. He seems to neatly explain the cosmic background radiation as well.

  23. Troy

    I don’t think it is that pretty. Compared to say Hyakutake on an icy moonless night.

  24. jess tauber


    Not to open can of wormholes- Gavin needs to learn that there are no absolute reference frames- ONLY ABSOLUTE SUBMISSION TO WORD OF DIRAC!

    Know that size is relative- maybe universe expansion is your ego (and atomic structure, among other things…) SHRINKING. You would never be able to tell, because all your rulers are shrinking as well, whereas OUR RULER (BLESSED BE THE RULER OF CREATION) NEVER SHRINK. BIG BANG RADIATION didn’t red shift- you blue shifted, because YOU ARE SO SMALL, AND SO SAD!


  25. Maurizio Morabito

    25 octillions of a megaton, i.e. 2.5E40 grams of TNT…comes out as a cube of explosive with a side of 250 million kilometers, right?

  26. Irishman

    BB Said:
    >This star blew up 100 million years ago, not in 2002

    A legitimate quibble buried in a matter of perspective. When discussing astronomical events, do we describe the the timeframes based upon when we see them occur, or when the signal was sent? From our perspective, the star blew up in 2002 – that is when we saw it occur. Okay, the light of the explosion didn’t reach us until 2002, but occurred some long time before. Drat!


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