London students spot nearby bright supernova
One of the brightest and closest supernovae since 1987 was discovered by a student group from University College London at an observatory in north London on 21 January. Meanwhile, Jupiter is unmistakable in the best evening sky of the year and both Mars and Venus are conspicuous before dawn.
The supernova, the catastrophic disintegration of a white dwarf star, is located in the galaxy M82, some 11.5 million light years away in the constellation of Ursa Major. At its brightest, perhaps as February begins, it may be shining at about magnitude 10.0. This is too dim to target through binoculars, unless you use large ones under a perfect sky, but it is easily seen through most amateur-owned telescopes provided we know just where to look.
At the star map times, M82 and its sister galaxy M81 are located 8° above the star Lambda high in the north-east at the end of the winding constellation of Draco. M81 lies 0.6° south (right) of M82 and is larger and brighter at about the seventh magnitude. M82 is the more interesting of the two because it appears to be a spiral galaxy in the throes of unusually rapid star formation – indeed it is classed as a starburst galaxy. Perhaps triggered by a close encounter with its neighbour, the episode means that M82 has a surfeit of luminous young stars and star clusters and, consequently, may host more than its share of supernovae.
We may now expect the current supernova, dubbed SN 2014J, to dwindle to obscurity over the coming months. Eventually, though, its debris may add another twist to the complex network of dusty filaments that do their best to hide M82’s spiral structure. It is interesting to note that all four of the brightest supernovae since 1993 have occurred in different galaxies in Ursa Major.
Jupiter stood at opposition on 5 January and is conspicuous as it climbs from the east at nightfall to stand high on the meridian at our star map times. Meanwhile the glorious shape of Orion the Hunter marches from the south-east to the south-south-west, followed by Sirius which lies 40° almost due south of Jupiter and is less than half as bright. Orion’s Belt points upwards to Aldebaran and the iconic Pleiades cluster and, as Orion stands at his highest in the south, look almost overhead for the bright star Capella in Auriga.
Besides the Pleiades, three other open star clusters are plotted on our southern star map. Praesepe, or the Beehive cluster, in Cancer is the brightest of these and best seen through binoculars. Look also for M35 near the feet of Gemini, and currently 10° to the west of Jupiter, and the slightly brighter M41 4° due south of Sirius.
There is still a chance to spot Mercury as it nears the end of its best evening show in 2014. Forty minutes after sunset on the 1st it stands almost 9° high in the south-west and 7° below the slender young Moon. Use binoculars to find it at magnitude -0.4, although it may become a naked-eye object before it sets in the west-south-west another 70 minutes later. By the 8th, though, the small innermost planet is 2.5° lower and one fifth as bright at magnitude 1.4 as it disappears into the twilight on its way to inferior conjunction on the near side of the Sun on the 15th.
Sunrise/set times for Edinburgh change from 08:07/16:46 on the 1st to 07:07/17:44 on the 28th. The Moon is at first quarter on the 6th, full on the 14th and at last quarter on the 22nd. It was new on 30 January and as it emerges in our south-western sky in early February, expect earthshine (“the Old Moon in the Young Moon’s Arms”) to be impressive. It is caused, of course, by the night side of the Moon’s disk being illuminated by the almost-full Earth in the lunar sky. The phenomenon will have disappeared before the Moon stands 7° below the Pleiades on the 7th, close to Aldebaran on the 8th and right of Jupiter on the 10th.
Jupiter dims from magnitude -2.6 to -2.4 as it creeps westwards in Gemini and shrinks to 42 arcseconds if viewed telescopically. With its active meteorology and four bright moons, it is a favourite for amateur observers, particularly now that it is highest in the evenings. The magnitude 3.6 star Lambda Geminorum, 9° south-east of Jupiter, disappears behind the southern limb of the Moon on the 11th. As seen from Edinburgh, the occultation lasts from 19:55 until 20:51.
Mars doubles in brightness from magnitude 0.2 to -0.5 as its small ochre disk swells from 9 to 12 arcseconds this month. The Red Planet is tracking eastwards 5° to the north of Spica in Virgo, rises in the east about ninety minutes after our map times and crosses Edinburgh’s meridian at a height of 26° almost six hours later. Saturn follows Mars across our southern morning sky to pass 17° high in the south at 06:50 on the 1st and almost two hours earlier by the 28th. The Moon is near Mars and Spica on the 19th and 20th and closest to Saturn on the 21st when Saturn is magnitude 0.5 and 17 arcseconds wide, with the rings tipped at 23° and 39 arcseconds broad.
Venus, at its brilliant best at magnitude -4.6 on the 11th, rises above Edinburgh’s horizon in the east-south-east at 05:58 on the 1st and 51 minutes earlier by the 28th. Look for it low in the south-east before dawn and catch it close to the waning Moon on the 26th.