The January Sky

Paul Curtin

Observers in parts of eastern North America will see the moon pass in front of the Pleiades near moonset on 18 January.

Mars is still very well placed for northern observers.

Winter in the north is dominated by Milky Way objects: bright stars, star clusters, and emission/reflection nebulae. Auriga contains all of these. This constellation, heralded in the east by bright Capella, occupies a large region north of Taurus. Its three Messier objects, M36-38, are fine open clusters. IC 417 and NGC 1931 are emission nebulae. Look for 417 around phi and 1931 between M36 and phi. Auriga also boasts a number of fine multiple stars.

Southeast of Taurus is the imposing figure of Orion. Unlike most extended celestial figures, Orion, with its bright stars and distinct pattern, immediately suggests a human form to first-time viewers. Its stars also provide a fine array of stellar type. Compare the bright red variable Betelgeuse with the blue-white double Rigel. The stars of Orion’s belt are actually the open cluster Cr70. The small triangle representing Orion’s head is the open cluster Cr 69. Both of these clusters are associated with emission nebulae and contain multiple stars worth locating. The series of emission and reflection nebulae that form Orion’s sword allow for hours of exploring. The most famous of these is M42, the Orion Nebula, centered around theta, the multiple star system known as the Trapezium.

South of Orion is the dipper of Lepus. The Milky Way veers to the east of this little constellation, and so we are left with a must less exciting region than that of its northern neighbor. Nonetheless, Lepus has a fine globular cluster, M79, south of beta, and a loose open cluster, NGC 2017, northeast of alpha. Lepus also hosts many multiple stars.

South of Lepus one finds rather sparse star fields. This is more than compensated by the view of the Large Magellanic Cloud in Dorado. Here we have the opportunity to explore some of the details of one of our sister galaxies. All the object types characteristic of our own Milky Way can be observed in our neighbor.

The Planets in January

Mercury can be observed at dusk during the second half of the month.

Venus steals the show in the morning sky this month. Only the sun and moon are brighter.

Mars is in Taurus and continues to stand out in the evening sky.

Jupiter can be glimpsed in the predawn sky, but you will need to wait a month or two to do any meaningful observations.

Saturn is in Leo and follows Mars in the evening 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.