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Saturn occults BY Cancri (TYC 1395--1113--1)
On the evening of 25 January 2006 Saturn will occult this star. Being of magnitude 8 (a little brighter than Titan, Saturn's brightest satellite) the event should be observable with telescopes working at powers of around x120. The star will appear to pass into the outer ring system at around 18h 45m passing the Cassini division 15 minutes later. From Orkney Saturn will be due east (to the left of the bright star Procyon, which the planet resembles in appearance to the unaided eye) at an altitude of 22º at 19h 20m. The event will end at approximately 20h 50m when the star emerges from the southern limb of Saturn itself. Fig. 2 shows Saturn in relation to TYC 1395--1113--1 and Titan at 18h 00m JV 16/01/06 Saturn in the Beehive Cluster January/February 2006 Saturn will be at opposition on 27 January and, at magnitude -0.2, is fractionally brighter than Capella which it closely resembles in colour. It is at present retrograding (moving east to west against the star background as seen from the northern hemisphere) at the rate of a little under 10 arc minutes in 24 hours. This is fast enough to be detected readily over this interval using a small binocular. Seen with the naked eye, Saturn appears almost halfway between the bright stars of Gemini and Leo and a little to the east (left) of the Beehive Cluster in Cancer. By opposition date Saturn will be close to the cluster itself passing a little below the centre on February 2 (Dia. 1). The Beehive Cluster (M 44) is an example of an open cluster and is seen with the unaided eye as a hazy patch of light. Again, a small binocular will show many of the stars to magnitude 9.
When as lad I was learning my astronomy in the 50s my grandfather drew my attention to the fact that Capella appears to twinkle rather more than most stars. At the time I was offered no explanation for this apparent fact. In winter the star is high in the southern sky but throughout our northern summers Capella skirts the northern horizon (more so from the lower latitudes of Britain). Perhaps the length of time Capella spends low in the northern sky accounts for the impression one has that it twinkles more than say Vega (barely circumpolar from London) and Arcturus, its rivals in brilliance? JV 4/1/06 Venus in the evening and morning sky January 2006 It has been refreshing to have a number of people telephone me, or just mention in passing, the brilliance of the planet Venus in the evening sky over the past few weeks. A glimpse of the planet low in the SSW sky shortly after sunset, when the twilight is still strong, will emphasize the brilliance Venus. But things move quickly even in the sidereal world. (Astronomers often emphasize the other extreme where phenomenon may only repeat themselves after thousands of years.) Venus was at maximum brilliance as recently as December 18, 2005, yet by January 13, 2006, Venus will be at inferior conjunction with the Sun. At this conjunction, which takes place close to midnight on the 13th, Venus will be 5.5º above the Sun. This means that for a few days either side of conjunction Venus will rise before the Sun and set after it. Indeed on the 12, 13, 14 January it may be possible to see the planet in both the morning and evening skies. The fact that Venus can be as bright as magnitude -4.0 at a conjunction, when its phase is a mere 0.4%, is attributable to the planet's comparative closeness to Earth (39.67 million kilometers) and the fact that some light is refracted around the limb. With an apparent diameter of 62.67" the very slender crescent should be readily visible in a small binocular with clear atmospheric conditions. Do not attempt to "sweep" for Venus with a binocular or telescope when the Sun still above the horizon. The same warning is offered to those with "go to" telescope mounts when attempting to observe Venus in full daylight. The risings and settings for Venus and the Sun are given below for the location of Orkney (Kirkwall): Venus Date Rise Set 11 Jan 2006 08:25:39 16:41:04
12 Jan 2006 08:18:10 16:35:25
13 Jan 2006 08:10:44 16:29:41
14 Jan 2006 08:03:22 16:23:54
15 Jan 2006 07:56:04 16:18:04
Sun Date Rise Set
11 Jan 2006 08:58:39 15:41:28
12 Jan 2006 08:57:27 15:43:29
13 Jan 2006 08:56:10 15:45:31
14 Jan 2006 08:54:50 15:47:37
15 Jan 2006 08:53:26 15:49:45
Not so early risers (some ferry crews will have been on the job for some time by then) may see Venus in the morning sky for around two weeks but by February twilight will begin to take over. Eastern elogations of Mercury and Venus. JV |
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