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The Andromeda Galaxy Just Had a Bright Gamma Ray Event

Posted by Unknown on from the alien-super-weapon dept.

First time accepted submitter SpaceMika (867804) writes "We just saw something bright in the Andromeda Galaxy, and we don't know what it was. A Gamma Ray Burst or an Ultraluminous X-Ray Object, either way it will be the closest of its type we've ever observed at just over 2 million light years away. It's the perfect distance: close enough to observe in unprecedented detail, and far enough to not kill us all."

6 of 129 comments (clear)

  1. False alarm -- just a normal background source by StupendousMan · · Score: 5, Informative

    The team which announced the event has now figured out that it wasn't interesting after all:

    TITLE: GCN CIRCULAR
    NUMBER: 16336
    SUBJECT: Swift trigger 600114 is not an outbursting X-ray source
    DATE: 14/05/28 07:57:12 GMT
    FROM: Kim Page at U.of Leicester

    K.L. Page, P.A. Evans (U. Leicester), D.N. Burrows (PSU), V. D'Elia (ASDC) and A. Maselli (INAF-IASFPA) report on behalf of the Swift-XRT team:

    We have re-analysed the prompt XRT data on Swift trigger 600114 (GCN Circ. 16332), taking advantage of the event data.

    The initial count rate given in GCN Circ. 16332 was based on raw data from the full field of view, without X-ray event detection, and therefore may have been affected by other sources in M31, as well as background hot pixels. Analysis of the event data (not fully available at the time of the initial circular) shows the count rate of the X-ray source identified in GCN Circ. 16332 to have been 0.065 +/- 0.012 count s^-1, consistent with the previous observations of this source [see the 1SXPS catalogue (Evans et al. 2014): http://www.swift.ac.uk/1SXPS/1....

    We therefore do not believe this source to be in outburst. Instead, it was a serendipitous constant source in the field of view of a BAT subthreshold trigger.

    This circular is an official product of the Swift-XRT team.

    Better luck next time.

    --
    Michael Richmond "This is the heart that broke my finger."
    mwrsps@rit.edu http://stupendous.rit.edu
    1. Re:False alarm -- just a normal background source by StupendousMan · · Score: 4, Informative

      And here's a very nice, easy-to-understand explanation of what happened, written by one of the SWIFT astronomers:

      http://www.star.le.ac.uk/~pae9...

      --
      Michael Richmond "This is the heart that broke my finger."
      mwrsps@rit.edu http://stupendous.rit.edu
  2. No, it's a ULX by buchner.johannes · · Score: 3, Informative

    http://www.star.le.ac.uk/~pae9...

    --
    NB: The message above might reflect my opinion right now, but not necessarily tomorrow or next year.
  3. Woops! Nevermind. by mbone · · Score: 4, Informative

    This has been withdrawn. From

    http://gcn.gsfc.nasa.gov/gcn/g...

    We therefore do not believe this source to be in outburst. Instead, it was
    a serendipitous constant source in the field of view of a BAT subthreshold
    trigger.

    This circular is an official product of the Swift-XRT team.

  4. Re:far enough by Kinthelt · · Score: 5, Informative

    It would instantly fry half the planet. The rest of the planet gets to die slowly.

    --

    "Evil will always triumph over good, because good is dumb." - Dark Helmet (Spaceballs)

  5. Apparently it was a false alarm... by johanwanderer · · Score: 4, Informative

    See here: http://profmattstrassler.com/2... "a known object in Andromeda that emits X-rays appeared to brighten, as a result of electronic noise in Swift’s instruments"