Xi Bootes in Little Cygnus

Xi Bootes, Double Star
Sketch and Details by Math Heijen

On the evening of May 9th 2008 I observed a series of double stars in Bootes. The highlight for me that night was Xi Bootes. This colorful double lies about 8 degrees east of Arcturus. The Yellow primary star shines at magnitude 4.8 and it’s magnitude 7.6 orange companion lies at a position angle of 315°. The separation is 6.3″. Through the 17mm Nagler the double looks fairly close (scale from “Double Stars for small Telescopes” by Sissy Haas). When looking at Xi Bootes through the 17mm Nagler, the double seems to be part of an asterism that looks like the constellation Cygnus, only much smaller. Xi Bootes is placed at the position of Deneb, the tail of the swan. We decided to call the asterism “Little Cygnus”. On the sketch below the asterism is oriented West-East. At the tail you find Xi Bootes. Three white stars oriented north-south represent the wings of the little swan. A white star to the east (accompanied by a dimmer companion) is at the position of the head of the swan. The yellow star to the eastern edge of the field of view is just a bright field star. It is no part of the “Little Cygnus” asterism.

The sketch of “Little Cygnus ” and Xi Bootes was made using the 300mm f/5.3 Dobson and a 17mm Type4 Nagler. The magnification is 94x and the field of view is 52′. At the telescope I made a sketch on white paper using a HB led-pencil. This sketch was scanned and processed in Photoshop. I colored the double star (and the field star to the east) using the tutorial described on the website of Jeremy Perez ( http://www.perezmedia.net/beltofvenus ). This is the first time I experimented with this technique, and I am very pleased with the result. It produces a realistic image and resembles what you see through the eyepiece. In the future I will try to use this technique for sketching more double and multiple stars.