Abstract
THE planets visible in the south-west sky in the evening are Mars andSaturn, and the approach of the former towards the latter will be noted, until, by February 2, Mars will have passed eastwards of Saturn. On January 20, Mercury is at greatest elongation (24° west) and may possibly be seen about 5° above the south-east horizon on that date at 7h. In the middle of the month, Sirius souths at 23h and is one of a conspicuous array of first magnitude stars to be seen southwards near the meridian. In order of apparent magnitude these stars are Sirius (—1·6m), Capella (0·2m), Rigel (0·3m), Procyon (0·5m), Betel-geuse (0·9m, variable), Aldebaran (l·lm) and Pollux (l·2m). Two of these stars offer extreme examples of stellar densities. There is Betelgeuse, a super-giant star with a diameter of about 250 million miles, the average density of which is one-millionth that of water. In contrast, the companion of Procyon, an extremely dense white-dwarf star of planetary dimensions, has a mean density more than a million times that of water.
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The Night Sky in January. Nature 141, 114 (1938). https://doi.org/10.1038/141114a0
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DOI: https://doi.org/10.1038/141114a0