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Images of Supernova 1998bp in NGC 6495

Images of Supernova 1998bp in NGC 6495

On this page you will find a list of images of SN 1998bp which was found in NGC 6495.

Other pages referencing this SN:

  • VSNet's sn1998bp we b page
  • Guy Hurst Light curve
  • M1 supernova search has a 1998bp page New 1/8/99

  • M.Armstrong discovery image 4/29/98
  • M. Armstrong images 4/29/98
  • CfA Spectrum 4/30/98
  • Ca' Bionda Observatory image Undated.
  • CfA image 5/1/98
  • Nick Hewit image 5/3/98
  • E. Prosper image 5/9/98
  • Gianluca Masi image 5/10/98
  • Josep MЄ Bosch image 5/20/98
  • Juan GonГalves and JoЦo Porto image 5/23/98 01:56:36 UT
  • Michael Schwartz image 5/27/98
    Yet another (potentially) bright SN has been discovered. Because the peculiarity is reported, it is worth monitoring further!

    Acoording to IAUC 6890 and 6891, SN 1998bp has been discovered by English amateur astronomer M. Armstrong on Apr. 29.074. The location of the new star is R.A. = 17h54m50s.71, Decl. = +18o19'49".3 (2000.0), which coincidents to about 15" north from the center of the host galaxy NGC 6495. Another astrometry given by A. Sugie, Dynic Astronomical Observatory, shows that the end figures of the position is 50s.72, 50".2. Reported CCD magnitudes are: Mar. 20.283, >16.7: Apr. 29.074, 14.8: 29.135, 14.7: 30.54, 14.9-15.1(V).

    Spectroscopy has performed by ESO group and Harvard group: they report that SN 1998bp is of type Ia around the maximum, but peculiar. ESO group mentioned that 635 nm (at rest) Si II feature is weak and many lines show P-Cyg profile. The color is rather red than normal SNe Ia, despite it seems not be reddened by scattering. Harvard group mentioned that the ratio of the deepness of Si II features (615 nm and 580 nm), which is thought to be an indicator of the intrinsic brightness of SNe Ia, is nearly equal to that of sub-luminous SN Ia 1991bg. However, the bluer region of the spectrum of SN 1998bp does not resemble that of 1991bg.

    The host galaxy NGC 6495 is a elliptical one. Its recession velocity is estimated by ESO group and catalogued in some references.

    CfA-redshift     3208 km s-1
    Di Nella et al.  3127         (A.Ap.Suppl, 113, 151 (1995))
    ESO group        4500
    
    These three indicate that NGC 6495 is not so near as Virgo cluster; it looks like about three or four times further than Virgo. Typical SNe Ia at this distance would expected to glow at 14.5-15.0 mag on maximum. Compared with the reported magnitudes, it is not likely that SN 1998bp is especially sub-luminous as 1991bg, as Dr. Taichi Kato noted.

    Followup photometry and spectroscopy is strongly encouraged. Particularly, because the decline rate after the maximum is thought to be another indicator of the luminosities of SNeIa, it is very important to develop the light curve.

    Sincerely Yours,
    Hitoshi Yamaoka, Kyushu Univ., Japan
    yamaoka@rc.kyushu-u.ac.jp


    Back to Supernovae in NGC and IC galaxies.
    David Bishop
    Last modified: Wed Jul 26 15:56:30 EDT 2000