Common problems

Most reported supernovae turn out to be false alarms. There are lots of checks and balances put in place to prevent false discoveries from getting posted on CBET Circulars, but sometimes a bad ones still gets through. The IAUC guidelines

Hot Pixels:

It is possible to have a hot pixel on your imager.   The way you can tell is to compare the size of the suspect to the size of a star of a similar brightness.   The hot pixel will be smaller then the foreground star, a supernova would be about the same size.


The supernova hunter's first line of defense is the CfA Minor Planet Checker. However, don't think that this is the last word. There are lots of uncharted asteroids out there, particularly on the ecliptic. This is why you want to take two images of any suspect. If the object has moved, then it was an asteroid. A very famous case is the case of 2003lr (local link).

Foreground Variables:

See the AAVSO online list of variable stars.   Here you can check for variable stars near the location of galaxies.   Also, look for high proper motion stars 2003aw

HII Regions:

An HII region can often produce a bright pixel in an underexposed image.  A second exposure can often verify this.

LBV stars:

Luminous Blue Variable stars are like Eta Carinae these are sometimes called "supernova imposters".   They are still worth reporting due to how rare these objects are.

Host nameLocationAssociated object
NGC 300 R.A. = 00h55m04s.86, Decl. = -37°41'43".7 2010da
NGC 1511 R.A. = 03h59m38s.07, Decl. = -67°37'54".6 Variable star in NGC 1511
NGC 3184 R.A. = 10h18m19s.89, Decl. = +41°26'28".8 2010dn
NGC 7259 R.A. = 22h23m08s.26, Decl. = -28°56'52".4 2009ip
MCG +06-49-68 R.A. = 22h39m58s.36, Decl. = +34o23'05".5 Variable star near Pegasus
2001bn    IAUC  8624    BV                anon
2001bh                7622    K star            ugc11635
2001dh                7482    M star            ic5374
1999db                7227    QSO             anon
1999dc                7227    AGN            anon
1999cx                7210    AGN            anon
1999cu                7210    AGN            anon
1999bs                7141    cat var           ugc11093
1998di                 6982    dwarf nova    anon
1993U                5818    QSO             anon
1993V                5818    QSO            anon
1992W                5517    M star        mcg 8-23-96
1992X                5517    M star         mcg 6-32-24
1991ap                5327    QSO          anon
1989Z                5162       var            ngc4013
1985J                 4059      CV            ugc6274
?                                        var            ugc10700

-            CBET    184        var            ugc11800
-                           197        var           ugc2495
2010db                2290      M star      ?
2005md                ?            CV          ngc2274
2007sv                 ?            BV           ugc5979
2006gy                ?            AGN?        ngc1260
2006fp                ?            BV            ugc12182
2006bu                ?            AGN        anon

Old Supernova:

If you want to search this page, the easiest way is to do a "view source" (Ctrl-u in Firefox), then do a find (Ctrl-f in Firefox) and look for "-00&deg" for any SN at -00° Declination.

Filters: Filter Equations

Back to Bright Supernovae.
David Bishop
Last modified: Fri Sep 1 16:26:58 EDT 2000