The October Sky

Paul Curtin


The Moon occults Regulus for observers in Europe and Southern Britain on the evening of October 7. See Kelly for details.

Northern observers should look for the Zodical Light before dawn after the 20th.

The first major constellation of the dark northern autumn is Pegasus. Look for a large empty square east of Delphinus. Follow the line formed by theta to epsilon westward to find M15, a lonely globular cluster. See Kepple and Sanner for finder charts to locate the multiple stars and galaxies of Pegasus.

South of the square of Pegasus is the circlet that comprises the western section of Pisces. This part of the constellation contains some multiple stars, but we will return to the more interesting eastern sector in November.

South of the circlet we move into Aquarius. Near epsilon is the globular cluster M72, the collection of stars known as M73, and the the bright planetary nebula NGC 7009, the Saturn Nebula. 7009 can be found roughly 3/4 of the way from epsilon to nu. North of this area we find two compact galaxy fields near the border with Equuleus. The globular cluster M2 is due north of beta. East of M2 is alpha, and east of this is the “water jar,” an asterism composed of gamma, pi, zeta and eta. Zeta is a fine double, both stars being yellow, that can be split with small telescopes. Due south is NGC 7293, the Helix Nebula.

The bright star dominating the darkness under Aquarius is Fomalhaut in Piscis Austrinus. Further south is Grus. Grus bears a slight resemblance to Cygnus but lacks the star clouds and nebulae of the northern avian.

The Planets in October

Mercury is a fine view for southern viewers in the first two weeks of October, but observers in the north must wait until November for a good view.

Venus is a very bright morning object throughout October.

Mars returns to the evening sky and begins to brighten. This is a good month to start observing in order to hone your skills for the December opposition.

Jupiter is still a good evening object for southern observers.

Saturn is in Leo and can be observed in the predawn sky.

Bibliography

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

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.