Galaxies NGC 3997, NGC 3993, NGC 3989
and NGC 3987
Supernova 2004aw in Leo

Supernova 2004aw:

• Discovered: March 19, 2004, by Tom Boles (UK); and independently by K. Itagaki (Japan).
• Magnitude 17.7 in the Kopernik image.
• Type: Ia
• The expansion velocity is about 12,600 km/s.

Follow this Link to a NASA Web site on supernovas. It has a very nice animation and a description of what these objects are.

Galaxies NGC 3997, NGC 3993, NGC 3989, and NGC 3987 in the Constellation of Leo are part of a galaxy group that also includes NGC 4000, NGC 4005, and perhaps several others. They all have nearly the same red shift and are roughly 250 million light years away. Edge-on Spiral Galaxy NGC 3987 was the host of Type Ia Supernova 2001v. A 2001 study using the Arecibo Radio Telescope shows the group to be immersed in a cloud of neutral hydrogen with complex structure that may include an extended tidal debris.

NGC 3997 is a disturbed and asymmetric Barred Spiral, with hints of a ring fragment north of center and a small blue condensation 0.4 south of center. Supernova 2004aw is located in the outer part of a very faint spiral arm. The galaxy is roughly 125,000 light years in diameter.

NGC 3997 Magnitude: 14.2 Constellation: Leo RA: 11h 57m 47.3s Dec: +25° 16' 18" Epoch 2000 Size (mins): 1.6' x 0.6' Classification: SBb pec        Barred Spiral, peculiar Dreyer description in the NGC:        "Pretty faint, very small, extended 25°, between 2 stars."	NGC 3993 Magnitude: 14.5 RA: 11h 57m 37.7s Dec: +25° 14' 32" Epoch 2000 Size (mins): 1.8' x 0.5' Classification: Sb:        Spiral, (uncertain) Dreyer description in the NGC:        "Very faint, pretty small, extended, 3 stars nearby."
NGC 3989 Magnitude: 15.7 RA: 11h 57m 26.3s Dec: +25° 13' 58" Epoch 2000 Size (mins): 0.6' x 0.3' Classification: Sbc        Spiral galaxy Dreyer description in the NGC:        "Extremely faint, very small, round."	NGC 3987 Magnitude: 14.3 RA: 11h 57m 26.3s Dec: +25° 11' 41" Epoch 2000 Size (mins): 2.2' x 0.4' Classification: Sb        Spiral galaxy Dreyer description in the NGC:        "Faint, moderately extended."

Click below to

George Normandin, KAS

April 21st, 2004