The July Sky

Paul Curtin

July arrives with the rising of bright white Vega (alpha Lyrae). The small parallelogram just south and east of Vega is the small part of Lyra. Note the fainter star northeast of Vega. This is epsilon Lyrae. Small telescopes show epsilon to be a double star, and greater magnification reveals that each member of this pair is itself double. Sweep slowly between the southernmost stars of the parallelogram for the ghostly smoke ring of M57, the Ring Nebula. Harder to find (lacking such distinct guide stars as those flanking M57) is M56, a very compact globular cluster near the southern border of Cygnus. To find it, follow the line formed by the southern stars of the parallelogram southeast halfway to Albireo (beta cygni) at the base of the Northern Cross.

South of Lyra and Hercules is the large kite-shaped constellation Ophiuchus, a region rich in open and globular clusters. Ophiuchus should be scanned carefully for deep sky objects. Though not as crowded as the star clouds to the east, this region contains a number of great objects for small telescopes.

Due south of Ophiuchus we find the distinctive shape of Scorpius, a constellation rich in deep sky objects. Antares (alpha Scorpii) is a red star that outshines all others in this part of the sky. Nestled close to Antares are two globular clusters, M4 and NGC 6144, with M80 further to the northwest. The Milky Way due east of Antares merits close scrutiny. Embedded in this region are a number of globular clusters, the most prominent being M19, M62 and NGC 6441. There are also numerous star clusters such as M6 and M7 not far from the ‘stinger’ of the Scorpion. In binoculars or rich field telescopes the star fields of Scorpius are truly stunning.

Southern observers can investigate the Milky Way in Norma. To the east, in Ara, the globular cluster NGC 6397 is a very fine object. Western Pavo and Octans have little of interest for small or mid-sized telescopes.


The Planets in July

Mercury is low in the morning sky.

Venus is an evening object.

Mars is a morning object throughout the summer.

Jupiter is in eastern sky after sunset.

Saturn, in Leo, is found in the early evening sky.


Bibliography

Archinal, B. A., Hynes, S. J., Star Clusters, Richmond, Virginia: Willman-Bell, 2003.

Burnham, Robert Jr., Burnham's Celestial Handbook, New York: Dover, 1978.

Hynes, S. J., Planetary Nebulae, Richmond, Virginia: Willman-Bell, 1991.

Kelly, P. (ed.), Observers Handbook 2007, Toronto: University of Toronto Press, 2006.

Kepple, G. R., Sanner, G. W., The Night Sky Observers Guide, Richmond, Virginia: Willman-Bell, 1999.

Tirion, W., Rappaport, B., Remaklus, W., Uranometria Deep Sky Atlas, Richmond, Virginia: Willman-Bell, 2000.

Webb, T. W., Celestial Objects for Common Telescopes, New York: Dover, 1962