Howard Astronomical League

This is a two-panel mosaic of 42 hours of exposures taken with an 8″ f/4 reflector and a QHY268M camera using Ha and OIII filters and RGB filters for the stars. The Flying Bat nebula (Sh2-129), discovered in the 1950’s, shows up in hydrogen alpha light and is here colored red and yellow. The Squid nebula (Ou4) was discovered by an amateur astronomer in 2011 and emits primarily oxygen III light, here colored blue green. The Squid nebula is extremely dim and one of the faintest nebulae I’ve imaged. While the distance to these objects is not at all certain, they are believed to be physically related with the Flying Bat being an HII region and the Squid believed to be the outflow from the bright star system at its center.

Sirius, the brightest star in the night sky, is orbited by a much fainter companion, “Sirius B.”  Orbiting its primary every 50-years, Sirius B is the closest example of a “White Dwarf Star.” White Dwarfs are stars that have aged past the Red Giant stage in their evolution and collapsed into a dense object that slowly cools. Although probably the size of the earth, Sirius B contains slightly more mass than our sun. A teaspoon full of the degenerate matter making up Sirius B would weigh over five tons on our earth. Likewise, I would weigh 66-million pounds should I wish to stand upon the surface of Sirius B.

Sirius B can be seen in this image as a tiny white dot just below its brighter companion. While Sirius shines at magnitude -1.67, Sirius B appears as magnitude 8.4 – fainter than Neptune! Moreover, they are currently separated by a tiny 10 arc seconds! To capture both stars. I imaged Sirius with a series of short 250-millisecond exposures. After stacking them, I processed the stack in the same way I tease Jupiter’s innermost moons out of the data.

Unfortunately, the result was a bit boring with no background stars and nothing to show the powerful glare of Sirius.  Therefore, I used a second stack of one-second exposures to show the powerful brightness of Sirius and the background stars.  I struggled with a way to represent both products on the same image, and decided just to inlay the shorter exposure containing the two stars atop the longer, prettier exposure.

As Sirius B progresses in its orbit throughout the upcoming years, its position relative to the background stars should be readily apparent.