Everything you wanted to know (or believed you knew) about the most well-known double star and two stars nearby, but were affraid to ask about.

One's work and hobby can have unexpected points of contact. While my heart is definitely set on stars, at present I earn my living in desktop publishing. Quite recently I realized that Adobe Photoshop, a software I routinely use to edit scanned images, lets users create their own filters, including a realistic gravitational lens simulator.

To tell the truth, it isn't a new discovery, since I have found it already several years ago. But Goldilocks' variable, though apparent on hundreds of published photographs of M 27 and conspicuous (due to its red color) on amateur CCD images of the planetary, still waits for a good long-term photometry to be officially accepted and named.

You may or may not know it was the German lithographer Wilhelm Tempel (1821–1889). Living and observing in Denmark, Italy and France, he discovered not only the most well-known reflection nebula (and some 150 other objects of the original NGC), but also dozens of asteroids and comets, including 55P/Tempel-Tuttle, the parent body of the Leonid meteor shower.

Think it was prepared by Ejnar Hertzsprung or Henry Norris Russell? Then visit my page that tells the true story. For those who like authentic sources, a facsimile of the historic article from the Astronomische Nachrichten is available (300 dpi scan converted to PostScript) along with its translation into English kindly prepared by Jan Hollan (Nicholas Copernicus Observatory and Planetarium Brno).

Article on my favorite globular cluster (much more interesting than famous M13 in Hercules). Originally written for Deep Sky Journal several years ago and later published in Monthly Notes of the Astronomical Society of Southern Africa (MNASSA), this piece is now extended, updated and first of all available online thanks to Hartmut Frommert, the webmaster of the SEDS Messier Pages.

One of the handbook byproducts is StarClock 2.0, a simple free program for PC/DOS machines with VGA graphics that animates stellar evolution in the Hertzsprung-Russell diagram. Based on a grid of models computed recently at Geneva Observatory. Look for the best site to download it.

Use just a ruler, a common calculator and two enclosed diagrams (available in PostScript) to find mass of Capella, the brightest star of Auriga and the textbook double-lined binary. The laboratory exercise based on spectroscopical data published by Barlow, Fekel and Scarfe ( PASP 105, 476, 1993), and observations with the Mark III interferometer (Hummel et al., Astron. J. 107, 1859, 1994 ).