Date/Time: July 16th, 1999, 5:19 UT
Date/Time: July 16th, 1999, 5:19 UT
This is a 10 minute exposure with an ST-6 CCD camera thru Kopernik's 20-inch F/8.1 Ritchey Chretien Cassegrain telescope. The field of view is about 5 x 7 arc minutes, with North at the top. Hazy and very hot and humid conditions caused a lot of noise in this image.
From IAU Bulletin 7219 (7/10/99):
A. V. Filippenko, U. of California at Berkeley, reports that a CCD spectrum obtained with the 3-m Shane reflector at Lick Observatory reveals SN 1999da to be of type Ia, but similar to the peculiar, subluminous type-Ia SNe 1986G or 1991bg. SN 1999da appears to be subluminous, and its host is an elliptical galaxy, consistent with previous indications that such type-Ia events tend to occur in elliptical galaxies.
In the Kopernik image above SN 1999da is about a magnitude brighter than when it was discovered.
Follow this Link to a NASA Web site on supernovas. It has a very nice animation and a description of what these objects are.
Elliptical Galaxy NGC 6411:
NGC 6411 is a typical elliptical galaxy. Since the brightness of ellipticals trails off gradually until the galaxy merges with the background, it is difficult to determine their exact size. In this case, SN 1999da appears to be outside of the galaxy. However, this just shows that NGC 6411 is much larger than it appears in the Kopernik image.
Dreyer's description from the New General Catalog(NGC): Very small, gradually brighter middle.
Based on the published red shift, a rough distance estimate for NGC 6411 and supernova 1999da is: 194 million light years, with the brightest part of the galaxy being at least 130,000 light years in diameter.
Click below to
George Normandin, KAS
July 17th, 1999