SPRING in the Northern Hemisphere means galaxies -- the evening sky is filled with them. One object worth keeping an electronic eye on is the Seyfert galaxy NGC 3786 in southern Ursa Major near the Leo border. Last October, while monitoring 50 active galaxies as part of my doctoral thesis, I observed this spiral undergo a major outburst at optical and infrared wavelengths. The event lasted several months with the visual brightness peaking around magnitude 14, about half a magnitude greater than preoutburst levels.
While many active galaxies are known to fluctuate (two other springtime objects, NGC 5548 in Bootes and NGC 4151 in Canes Venatici, being the best-studied examples), NGC 3786 had no previously reported variability. This galaxy appears to be interacting with another spiral, NGC 3788, several arcminutes to the north. Continuous monitoring of this active galaxy is very desirable since such data may lead to a better understanding of the emission mechanisms within active galactic nuclei. NGC 3786 is well within the reach of modest backyard telescopes equipped with CCDs. Anyone wishing to participate in a monitoring project is encouraged to contact me for more detailed observing information.
Brant Nelson
Dept. of Astronomy
University of California at Los Angeles
Los Angeles, CA 90024