Choosing A Telescope
Telescope Aperture Considerations
Introduction to Planetary Sketching
Refractor Dobsonian Style Mounts
The Bonds: Pioneers of American Astronomy
Saturn's Encke Minima and Encke Division
Nature and Travel Photography
Recommended Astronomy Books
Original drawing made using white pencil on black paper:
Same drawing on a white background:
June 7-8, 2002 10:45 PM - 1:05 AM, seeing 5-6, limiting magnitude 5.6. North is to the lower right.
Astro-Physics 7.1" f/9 EDT refractor on homemade Dobsonian-style mount. Magnification 29x to 162x.
M 51 (NGC 5194) is a spiral galaxy located in the constellation of Canes Venatici. NGC 5195 is located at the end of one of its spiral arms. M51 has a magnitude is 8.4, diameter of 11.2' x 6.9', and is approximately 15 million light years away. It was discovered by Charles Messier in October 1773. M 51 is similar to our galaxy and M 31 in terms of luminosity, size, and mass.
Observing it on May 12, 1787 William Herschel described it as "Bright, a very uncommon object, nebulosity in the center with a nucleus surrounded by detached nebulosity in the form of a circle, of unequal brightness in three or four places, forming altogether a most curious object".
Messier described it as "Very faint nebula without stars".
Through the eyepiece the connecting arm between M51 and NGC 5195 was visible. The core of the satellite galaxy NGC 5195 appeared brighter than the core of M 51, and somewhat more star like. The central region of M 51 is larger than that of NGC 5195, and appeared mottled. I was able to see two dust lanes, one to the north and the second to the southwest of the central region of M 51. Several spiral arms were visible, one to the outside of each dust lane, and one on the inside of a dust lane to the right of the central region of M 51. A brighter area was noted in this spiral arm.