Monthly Archives: January 2014
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.
This is a slightly-revised version of Alan’s article published in The Scotsman on January 31st 2014, with thanks to the newspaper for permission to republish here.
Jupiter and Orion rule our New Year nights
The annual Quadrantids meteor shower hits its intense peak even before Jupiter comes to opposition on the 5th. The giant planet shines brightly throughout our January nights and Orion, too, is ideally placed in a sky awash with bright stars.
What is missing, though, is any sign of Comet ISON. Any hopes that the comet might blossom into a spectacular sight during December were shattered when its icy nucleus failed to survive its brush with the Sun on 28 November. A so-called ghost of ISON did emerge from its perihelion, but this must have been a dispersing cloud of dust which soon disappeared. Searches since then, including by Hubble, have failed to spot anything at all. So much for the Comet Of The Century.
Our charts show the Pleiades in Taurus glimmering high in the south at our map times as Orion strides towards the meridian. Trailing Orion are his two dogs, Canis Major and Canis Minor, with their bright stars Sirius and Procyon. Together with Betelgeuse at Orion’s shoulder, these form the Winter Triangle. Orion’s immediate foe, of course, is Taurus the Bull whose main star Aldebaran lies against a more remote V-shaped star cluster, the Hyades. The tips of the bull’s long jutting horns are marked by the stars Elnath and Zeta Tauri and it is just 1.1° north-west of Zeta that we find the famous Crab Nebula. The debris from a supernova explosion recorded by Chinese astronomers in 1054, it lies about 6,500 light years away and appears as an oval eighth magnitude smudge through a telescope.
January sees the Sun climb 6° northwards as sunrise/sunset times for Edinburgh change from 08:43/15:49 on the 1st to 08:09/16:44 on the 31st. The Moon is new on the 1st, at first quarter on the 8th, full on the 16th, at last quarter on the 24th and new again on the 30th.
With no moonlight, and if the weather permits, this could be good year for Quadrantid meteors. The shower lasts from the 1st to the 6th but has an unusually brief peak when the meteor rate could reach 80 or so per hour for an observer under ideal conditions. That peak is expected at about 19:00 GMT on the 3rd when the radiant, the point in the sky from which the meteors diverge, lies rather low in the north so that only a fraction of the ideal number of meteors may be seen. Even so, I’d expect to see several long-trailed meteors speeding overhead from north to south. Later in the night, the radiant follows the Plough as it climbs through the eastern sky.
The brightest object on our charts, Jupiter, shines at magnitude -2.7, three times brighter than Sirius, when it stands opposite the Sun on the 5th. It then rises in the north-east at sunset, crosses our high meridian at midnight and sinks to set in the north-west at dawn. The arrow on our chart shows it tracking westwards against the stars of central Gemini, some 10° below and right of Castor and Pollux. As such, it is unmistakable above and to the left of Orion later in the night. Look for it to the left of the almost-full Moon on the evening of the 14th. Jupiter is 630 million km distant at opposition, its slightly rotation-flattened disk measuring 47 arcseconds in diameter.
Appearing even larger than Jupiter is the dazzling magnitude -4.3 evening star Venus which sinks from 10° above Edinburgh’s south-western horizon at sunset on the 1st to set itself 100 minutes later. A full arcminute in diameter but only 4% illuminated, its slender crescent is obvious through binoculars. Weather and horizon permitting, the view may be more stunning on the 2nd when Venus lies 2.7° below-right of the narrow arc of the 2% illuminated Moon.
Venus soon disappears from our evening sky as it sweeps through inferior conjunction on the Sun’s near side on the 11th. Within another four or five days, though, Venus reappears as a morning star in the south-east and by the 31st it rises two hours before the Sun, shines at magnitude -4.6 and is a 12% sunlit crescent 52 arcseconds across.
Mercury emerges as an evening star later in the month as it moves to lie 18° east of the Sun on the 31st. Between the 19th and 31st, its altitude in the south-west forty minutes after sunset doubles from 4° to 8° as it dims only slightly from magnitude -0.9 to -0.5. Use binoculars to spy it in the twilight if you have a favourable horizon.
Mars rises in the east in the middle of the night and is tracking eastwards against the stars of Virgo to pass 5° north of Spica on the 28th. Its pink-red glow brightens from magnitude 0.8 to 0.3 and its disk swells to 9 arcseconds by the month’s end, large enough for some surface detail to be visible telescopically. It is best to observe it when it is highest as it crosses the meridian at an latitude of almost 30° shortly before dawn. The Moon lies alongside Spica and below Mars on the 23rd.
Saturn, another morning object, is creeping eastwards in Libra, about 6° to the east (left) of the wide double star Zubenelgenubi. It rises in the east-south-east at about 04:20 on the 1st, two hours earlier by the 31st, and at mag 0.6 to 0.5 is the brightest object low down in the south before dawn. When it lies alongside the Moon on the 25th, its disk appears 16 arcseconds wide while its glorious rings are 37 arcseconds across and have their north face tipped 22° towards us.