Supernovas are discovered in distant galaxies almost daily, literally!  This one was discovered 2002 March 9.08 UT.   It is located in the constellation Leo, at a declination that is convenient for northern hemisphere observers.  It also "transits" at a conventient time, about 11 PM.  This means it is available for viewing almost the entire night, and is overhead at a time when city lights begin to dim and the sky becomes darker.  Since it will be "viewable" for at least 3 months, it should be possible to establish a "light curve" (brightness versus time) during a significant portion of its decline phase.

Unfiltered image of the galaxies NGC 3190 (center), NGC 3187 (upper-right) and NGC 3193 (upper-left).  NGC 3190 is a normal spiral galaxy, NGC 3187 is a barred spiral galaxy and NGC 3193 is an elliptical galaxy. A supernova is located to the lower-left of the center of NGC 3190. At the time of this exposure the supernova was approximately 5 days old. The image has dimensions of 14 x 9 'arc, and the star images have a "full-width-half-maximum of 4.6 "arc.  The faintest stars are about magnitude 19.4. The supernova has a magnitude of 15.1 at this time, March 12.13 UT. [10-inch Meade LX-200, f/6.3 Schmidt-Cassegrain telescope, Meade 416XTE CCD, Meade 616 filter wheel; average of 6 images, total exposure 12 minutes; Santa Barbara residence, 200 ft ASL; 2002.03.11/12]

This color image has contrast and brightness adjustments to emphasize the faintest regions.

A reduced contrast and brightness version of the same image now shows the supernova at the edge of the central bulge.

A lower brightness version clearly shows the supernova.

When a supernova is close to the galaxy center, or even within a spiral arm that is bright, it is difficult to measure the supernova's magnitude.  Consider the following image, which is an enlarged portion of the first black-and-white iamge.

The supernova, SN2002bo, is inside the circle.  The surrounding annulus if used for calculating a "reference level" for magnitude estimates.  The upper part of the reference annulus contains galactic emission, which will render the supernova's brightness slightly reduced from its true value. It is important to keep the inner circle and annulus as small as possible in order to minimize these problems.


This site opened:  March 13, 2002 Last Update:  February 3, 2003