Supernova 1999gn in M61

This page is devoted to information on Supernova 1999gn in NGC 4303 (= M61) Basic information on this SN, including the last reported brightness, on this Supernova can be found on the main supernova page. Information on the original web pages for many of these images can be found on the Supernova links web page.

sn99gn.jpg Amateur Alessandro Dimai reported via ISN his discovery of a new star in M61. According to the rules, amateurs need two observations on two different nights to confirm a new supernova. Thus, ISN activated its' "isn_alert" SIG, which puts us in contact with amateur and professional supernova hunters around the world. Within hours, Weidong Li from LOSS had confirmed his observations and it was off to IAU for an official designation.

Web pages dedicated to this SN.

  • AUDE has a 1999gn page in French [Translate]
  • SEDS has a Supernova 1999gn page.
  • AAVSO issued aavso-alert 268 with information on this SN and some very nice finder charts
  • Seiichi Yoshida has a 1999gn page
  • Discovery of supernova in M61 in Italian [Translate]
  • ESA Science story Armchair astronomy - catch a supernova from home? Relinked 7/26/00
  • Odd Trondal's 1999gn page
  • Kopernik's M61 and supernova 1999gn page

    The following is a list of images of this SN, in chronological order. Click on the name in the "observer" column to see the image. Times and dates are in UT unless otherwise noted. If you know of any others, please tell me!
    Alessandro Dimai image 12/17.219/99CDiscovery
    CROSS image 12/17.22/99Ccolor, (tiff version)
    Odd Trondal image 12/20.173/9916.0:CAir turbulent
    KenIchi Kadota
    Seiichi Yoshida image
    12/20/99 1:44 JST15.7C
    KenIchi Kadota
    Seiichi Yoshida image
    12/22/99 5:53 JST15.7C
    Larry Robinson image 12/25/99C
    Arno van Werven image 12/26.349/99C
    Rok Palcic image 12/31/99C mirror
    K. Sárneczky, L. Kiss
    K. Sziládi image
    Ramon Naves image 1/1.850/00C
    Rafael Ferrando image 1/2.140/0015.5C
    S. Moretti image 1/3.1/00C
    L Brunetto image 1/3/0014.6C
    Marko Moilanen
    Arto Oksanen image
    Arno van Werven image 1/11.401/00C
    Odd Trondal image 1/28.147/0016.5C
    Ron Wodaski image 1/28/00C
    KenIchi Kadota
    Seiichi Yoshida image
    1/29/00 2:30 JST16.2C
    Don Dillinger image 2/10/0016.3C
    Johannes Walter image 2/12.073/00C
    Odd Trondal image 2/14.0208/0016.8C
    Stephen M. Brincat image 2/25.935/0016.2V
    Rafael Ferrando image 2/27.099/0016:C
    KenIchi Kadota
    Seiichi Yoshida image
    2/29/00 1:21 JST16.2C
    P Pinel image 3/5.029/0015.7C
    Fred Ewalt image 3/6.950/0016.06C
    JM Llapasset image 3/9.926/0015.4C
    Rafael Ferrando image 3/11.095/0016:C mirror
    Fred Ewalt image 3/24.090/0015.62CR
    Chris Spratt image 3/31.268/00C
    Kopernik image 4/1.243/0015.5C
    Tom Davis image 4/5.146/00C
    Chris Spratt image 4/5.213/00C
    JM Llapasset image 4/24.920/00C

    Light curves and Spectra:

  • VSNET Light curve (requires JAVA).
    If you have observations of this Supernova, please send them to Use this VSNet data query to see what information has been reported so far. Other VSNet data on this SN:
  • [vsnet-alert 3835] SN 1999gn in NGC 4303 = Messier 61
  • [vsnet-chat 2469] Host galaxy of SN1999gn
  • [vsnet-alert 3842] Spectroscopy of SN 1999gn
  • [vsnet-alert 3845] T&B sequence for M61

    Latest Photometry:

  • [vsnet-alert 3847] SN1999gn early photometry (update)
  • [vsnet-alert 3860] SN1999gn rising!
  • [vsnet-recent 48577] SN1999gn recent (cont'd)
  • [vsnet-recent 52603] SN1999gn recent (cont'd)
    Back to 1999 Supernovae
    Back to Bright Supernovae.
    David Bishop
    Last modified: Wed Jul 18 12:52:31 EDT 2001