Astronomers get best and earliest view of supernovae ever


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Using ground-based telescopes as well as the space telescope Kepler astronomers have obtained their best and earliest view of a Type Ia supernova.

The supernova, named SN 2018oh, was brighter than expected over the first few days. The increased brightness is an indication that it slammed into a nearby companion star. This adds to the growing body of evidence that some, but not all, of these thermonuclear supernovae have a large companion star that triggers the explosion.

Las Cumbres Observatory (LCO), based in Goleta, California, is a global network of 21 robotic telescopes that obtained some of the best data characterizing the supernova in support of the NASA mission. Wenxiong Li, the lead author of one of three papers published today on the finding, was based at LCO when much of the research was underway. Five other LCO astronomers, who are affiliated with the University of California Santa Barbara (UCSB), also contributed to two of the papers.

Understanding the origins of Type Ia supernovae is critical because they are used as standard candles to map out distances in cosmology. They were used to discover Dark Energy, the mysterious force causing the universe to accelerate in its expansion. Astronomers have long known that a supernova is the explosion of a dense white dwarf star (A white dwarf has the mass of the sun, but only the radius of the Earth; one teaspoon of a white dwarf would weigh roughly 23000 pounds) What triggers the explosion is less well understood. One theory holds that the explosions are the merger of two white dwarf stars. Another is that the second star is not a white dwarf at all, but a normal-sized or even giant star that loses only some of its matter to the white dwarf to initiate the explosion. In this theory, the explosion then smashes into the surviving second star, causing the supernova to be exceedingly bright in its early hours.

Finding that Type Ia supernovae can be brighter than previously believed throws a wrench into the results that discovered dark energy, since those results made assumptions about the brightness and thus the distance of those supernovae. If the brightness of these supernovae are not as reliable as expected, they are also less of a standard candle for estimating distance.

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8 comments

  • Lee S

    Giving it all a long think…. Would faults in the the reliance of supernovers as standard candles make more sense than dark energy?
    I smell new physics on the horizon…

  • wayne

    Lee S-

    You might like this:
    –a good overview-
    Terence Tao: The Cosmic Distance Ladder
    UCLA 2010
    https://youtu.be/7ne0GArfeMs
    1:16:15

    Interesting factoids-
    Estimate (2004) diameter of the entire Universe= 78 billion light-years.
    Most distant object detected (gamma-ray burst) = 13 billion light-years.
    Diameter of observable Universe= 28 billion light-years.

  • wayne

    Just for Fun:

    Pink Floyd –
    Speak To Me & Breathe
    https://youtu.be/Z-wKXP7s2gY
    7:14

  • wayne

    Pink Floyd –
    “Set The Controls For The Heart Of The Sun”
    >paired with some very nice “Mars Direct” animation
    https://youtu.be/a9ntxCcjVjE
    9:47

  • Lee S

    Wayne….. Thank you for the link…. I had plans on going to.the pub tonight…. But stayed home, chugged a couple of glasses of wine and watched this lecture… Fascinating stuff! Thank you!

  • wayne

    Lee S:
    (are you in Canada? I forget.)

    -You might enjoy this Roger Penrose lecture as well (–even if you don’t like his conclusions or his Conformal Cyclic Cosmology theory–) he does an excellent job setting up his proposition, and explaining how he arrived at it. Lots-o-great factoid’s– his discussion of light-cones alone is worth it. (and explains how the diameter of Universe can be “78 billion L-Y” while only being 13.7 billion years old.)
    (– he’s the Master of the Overhead Projector and does all his own slides–)

    Sir Roger Penrose,
    “Aeons before the Big Bang”
    (Copernicus Center Lecture 2010)
    https://youtu.be/4YYWUIxGdl4
    1:57:35

  • Lee S

    Thanks Wayne… That’s another evening at the pub I missed!! :-)
    I need to re watch the last half… My whisky glass got refilled a little too much….
    I’m so glad that that Minds immeasurably superior to ours ;-) are pondering the huge questions….

  • wayne

    Lee S-
    (Get yourself some Crown Royal Extra Rare, and stay inside for the Winter!)

    Personally, I enjoy Dr. Penrose immensely. (He is however getting older, very fast. You can see the difference between his 2010 presentations, and his more recent talks.) I’m all-in, on Conformal Cyclic Cosmology, it’s very elegant, he addresses the entropy problem, and it doesn’t rely on inflation.
    If you want further mind-boggling stuff from him, search his “palatial twister theory,” and/or “forbidden crystal symmetry.”

    His most current book is:

    “Fashion, Faith and Fantasy in Physics
    Sir Dr. Roger Penrose 2017
    https://youtu.be/iH4XJHJ8AOw
    1:03:45

    “Can the following of fashion, blind faith, or flights of fantasy have anything seriously to do with the scientific quest to understand the universe? Surely not – but Roger Penrose argues that researchers working at the extreme frontiers of physics are as susceptible to these forces as anyone else, and that fashion, faith, and fantasy, while sometimes highly productive in physics, may be leading today’s researchers astray in three of that field’s most important areas—string theory, quantum mechanics, and cosmology.”

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