Posted by on May 26, 2013 in Constellation Of the Month, News |

Summer is generally regarded as the worst time for stargazing. It is true that the period of darkness is short and that the brilliant winter constellations are out of view. But the summer skies are certainly not devoid of interest. There are several legends associated with Cygnus the Swan. According to one of these, Jupiter changed himself into a swan when he wanted to visit Leda, wife of the Spartan King Tyndarus, for reasons, which are rather obvious; he felt it desirable to remain strictly incognito. In memory of the story he placed a sawn in the sky.

Cygnus is often and more appropriately, referred to as the Northern Cross, and is so prominent that it may be identified at almost the first glance. One star of the cross Albireo, is fainter than the rest, since it is below the third magnitude. But it makes up for this by being a superb double star, with a golden-yellow primary and a greenish or bluish companion. Any small telescope will show it well, and it is probably the most beautiful object of its kind in the whole sky. Deneb does not appear so conspicuous as Altair or Vega, since it lies at a great distance from us, but it is exceptionally luminous. It is slightly yellowish in hue. Between Sadr and Albireo lies the star Eta Cygni, magnitude 3.89. Close to it is a long period Mira type variable, Chi Cygni. It changes between magnitudes 4 and 14. Telescopes of considerable size are needed to show it all. Since the Milky Way flows through Cygnus, the whole constellation is rich, and sweeping the area with binoculars of a low power telescope will reveal some magnificent star fields.

Star Visual Magnitude Spectrum Absolute Magnitude Distance (Lt Years)
Deneb 1.25 A2la -8.73 1550
Sadr 2.23 F8lb -6.12 1523
Gienah 2.48 K0III 0.76 72
Rukh 2.86 B9.5III -0.74 171
Albireo 3.05 K3II+… -2.31 385


M-39 Through binoculars, this open cluster is very impressive. It is large and bright. It stands out well from the background. It has an overall triangular shape, but does loose some of its impact, because of its size and the fact that it is not very concentrated to the centre.

M-29 This small open cluster is seen through binoculars as a diamond shaped grouping of about 6 to 8 stars in a nice field. In a telescope, the count increases to about 15 sparsely concentrated stars.

NGC 7000 The North American Nebula. I usually see this best with the naked eye as a milky patch just to the east of the bright star Deneb. The ‘Gulf of Mexico’ region stands out particularly well. Try holding an O-III or UHC filter in front of your eyes to increase the contrast. Then as an added treat, use these filters while looking through binoculars.

NGC 6969/6992-5 The Veil Nebula. This is a large supernova remnant best seen at low power, divided into two major segments.

NGC 6960 Is the more difficult to see, as the bright star 52 Gygni overwhelms it. NGC 6992-5 lies to the east, and shows a wealth of filamentary detail, especially when using a filter.