Starwatch: The February night sky

Graphic: Finbarr Sheehy

Most of the elements that excited starwatchers in January are still with us, though Comet Lovejoy is now fading and may be close to the fifth magnitude as you read this. For a chart of its motion as it passes close to the star Almach in Andromeda this week refer back to our previous Starwatch on 12 January. At its best at around that time its diffuse green head reached mag 3.8 or so, making it a naked eye object in dark skies.

The glorious winter sky around Orion is now perfectly placed for prime time viewing, while Sirius scintillates furiously on the meridian at our map times. There is a rendezvous between Mars and the brilliant Venus as the night begins, and Jupiter is at it prominent best for the year as it comes to opposition on the 6th.

Visible low in the E as the night begins, the giant planet shines at mag –2.6 (brighter than Sirius) as it climbs into the SE by our map times and the S by the middle of the night. Look for it to the right of the Sickle of Leo and near the full moon on the 3rd/4th. While a telescope shows Jupiter’s cloud-streaked 45-arcsec disc, we need only decent binoculars to glimpse the changing pageant of its four main moons as they swing from side to side.

Venus, brilliant at mag –3.9, climbs 8° higher in the SW at nightfall and sets in the W almost 3 hours after the Sun by the month’s end. Mars, reddish and 100 times dimmer at mag 1.2, lies 9° above-left of Venus on the 2nd and 0.8° below Venus on the 20th when both planets stand 4° above-right of the impressively earthlit young Moon. Venus slips 0.5° S of Mars a day later and lies 3° above and to its left by the 28th. Telescopically, Venus shows a 10 to 11 arcsec gibbous disc while Mars is only 4 arcsec wide.

Mercury is too low in the dawn twilight to be seen from Britain. Saturn, though, is the brightest object low in our SE to S sky in the hours before dawn. Shining at mag 0.5, it stands 9° above-right of Antares in Scorpius and is creeping slowly eastwards just above the double star Graffias. Catch it to the right of the Moon on the 13th when its globe and rings measure 16 and 37 arcsec wide respectively.