THE SOUTHERN HEMISPHERE
With Glenn Dawes
Look out for a meeting of six planets in the evening sky, and enjoy a view of Orion’s brightest star Rigel
When to use this chart
1 Jan at 00:00 AEDT (13:00 UT) 15 Jan at 23:00 AEDT (12:00 UT) 31 Jan at 22:00 AEDT (11:00 UT)
JANUARY HIGHLIGHTS
Following the Great Conjunction of Jupiter and Saturn, the gas giants drop into the evening twilight. Mercury enters the evening sky, passing them as they prepare to exit; on the 11th it has its closest approach to Jupiter, only 1.5° away. Although low in the twilight glow, the planets should be visible a few degrees above the horizon, 30 minutes after sunset. On the 14th, the thin crescent Moon joins in, only 1.5° from Mercury with Jupiter 4° below.
THE PLANETS
Observe six planets in the evening sky! As mentioned above, Jupiter and Saturn are in the western twilight sky and can be caught early in the month. Mercury has a generally poor evening apparition in January, low in the solar glow and best
DEEP-SKY OBJECTS
The brilliant star Rigel (Beta (b) Orionis), along with Betelgeuse (Alpha (a) Orionis), shines out in the constellation of Orion, the Hunter. As well as being the 7th brightest star, Rigel is also a double, a pair of blue stars of mag. +0.2 and +6.8, separated by 9.5 arcseconds.
Next up, an unusual object in neighbouring Monoceros. Almost 11° east of Betelgeuse, lies the nebula
The chart accurately matches the sky on the dates and times shown for Sydney, Australia. The sky is different at other times as the stars crossing it set four minutes earlier each night.
STARS AND CONSTELLATIONS
One of the brightest Mira-type variable stars, S Carinae, HD 88366, is located near the Eta (η) Carinae Nebula. Its brightness ranges from around sixth to ninth magnitude over a period of 149 days and is easily followed with binoculars. The star is expected to be near a minimum in January rising to a maximum in April, the best time to follow Carinae in the evening sky. Locator information can be obtained from the American Association of Variable Star Observers at www.avso.org. around the week of the 20th. Neptune should be the next, departing around 22:00 mid-month. The evening feast concludes with Mars and Uranus, setting around midnight mid-month. Meanwhile, Venus remains low in the eastern dawn sky. complex of NGC 2264. Only 1° south is Hubble’s Variable Nebula – NGC 2261 (RA 6h 39.2m, dec. +8° 44’). It’s only 2 arcminutes long and resembles a comet. A faint star, R Monocerotis, forms the nucleus with the nebulae fanning out northwards – the tail. Over the years its brightness and visible size has changed, thought to be due to a combination of R Monocerotis being variable and shifting clouds casting shadows on the nebula.
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