Galaxy Zoo Talk

Visible SDSS Supernova

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    SDSS visible Supernova SN 2004bh, and apparantly by chance coincidence was targeted by SDSS for taking spectrum. I've also checked the MJD date of the SDSS image and this is nearly the same as the discovery date.

    Apart from this it looks very white instead of the usual assumed SDSS blue / green.

    enter image description here

    enter image description here

    http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?id=1237665097390817477

    Spectrum certainly matches the description:

    SN 2004bh is of
    type II, perhaps II-L, at an early stage of development. The
    spectrum is dominated by H_alpha emission, with little
    corresponding blueshifted absorption. Weak Ca II near-infrared
    triplet absorption is also visible.

    http://www.cbat.eps.harvard.edu/iauc/08300/08331.html#Item1

    Report on the TNS (is the reported position off??) https://wis-tns.weizmann.ac.il/object/2004bh

    PanSTARRS image:

    enter image description here

    Posted

  • Budgieye by Budgieye moderator

    That isn't the spectrum of a supernova. The problem is that the spectrum was taken months after the initial photo, and the supernova will have faded by then. (I say this without actually checking the dates)

    image mjd_g 5.31102261E4 53110 April 15, 2004

    spectrum mjd 53385 Jan 15 2005

    Here is a modified Julian date converter http://pdc.ro.nu/mjd.cgi

    enter image description here

    If you look at the spectrum, you will see that it has all colours of the spectrum, a flat line. So what you are seeing is basically white. There is a one thin peak in the red,at 7000 Å that corresponds to the red in the nucleus.

    enter image description here

    Page 3 Spectra Guide for Galaxy Zoo Talk http://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3

    Oh, pooh, I had done this same thing 2 years ago.

    Super nova SN 2004bh visible https://talk.galaxyzoo.org/#/boards/BGZ0000004/discussions/DGZ0000yfq

    Here is a supernova spectrum. there is a big peak in the green.

    enter image description here

    https://www.cfa.harvard.edu/supernova/RecentSN.html

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Hmm didn't think of checking the spectrum MJD date.

    Then it's strange they took a spectrum of an 'empty' part of the galaxy instead of the nucleus, were there was a supernova 9 months earlier, and it exactly matches the SN spectrum description, and the SN is indeed white as you describe the spectrum.

    SN 2004bh is of type II, perhaps II-L, at an early stage of development. The spectrum is dominated by H_alpha emission, with little corresponding blueshifted absorption. Weak Ca II near-infrared triplet absorption is also visible.

    enter image description here

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Oh, pooh, I had done this same thing 2 years ago.

    😃 AGZ0002kpc AGZ0002kpd AGZ0002kpe AGZ0002kpf

    Makes me wonder how many times the same thing is 'discovered' again when an object gets a new GZ ID.

    Posted

  • Budgieye by Budgieye moderator

    Many times. To check Talk and Forum using various ObjIDs, it might be necessary to do as many as 20 searches, which is getting too much like real work, and it is faster just to do the science staff again.

    I have asked for our version of street view to pin discussions.

    I have done the forum search below using 1237665097390817477

    Forum: Re: Sought: AGN with big companion galaxies egalaxyhttp://www.galaxyzooforum.org/index.php?topic=279841.msg581410#msg581410

    Forum: Re: supernovae thread by c_cld http://www.galaxyzooforum.org/index.php?topic=4767.msg574040#msg574040

    and 587739376165912634 which has 6 discussions, one in the supernova thread Forum Re: supernovae thread by jlowe http://www.galaxyzooforum.org/index.php?topic=4767.msg84570#msg84570

    Using http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?ra=145.23487255&dec=27.77996818 , zero results in Talk, and I don't think we used that ID at the time that Forum was operating.

    Posted