Meteors hail New Year as Mars doubles in brightness

OUR January evenings are illuminated by the two brightest planets and the richest grouping of constellations in the entire sky, while two other planets grace the southern sky before dawn. If the weather allows, we may also enjoy an intense meteor display next Wednesday morning.

That meteor shower, the Quadrantids, lasts from the 1st to the 6th but is expected to unleash most of its meteors during a spell that lasts for just a few hours around 06:00 on the 4th. The point from which they appear to emanate, the radiant, lies in what is now northern Bootes but once belonged to the now-defunct constellation of Quadrans Muralis, hence the shower’s name.

That point stands low in the north at our chart times (see north map) but follows the Plough as it climbs through the north-east and east after midnight. By 06:00 meteors should be raining down in all directions, with their paths pointing back to the radiant some 65° high in the east. The gibbous Moon sets more than two hours earlier, so meteor rates could approach 60 to 200 per hour under ideal condition.

With the Pleiades glimmering high on the meridian, and with Orion resplendent in the south-east, the sky at our map times is bursting with stellar interest. If the Moon is not a hindrance, try to spot the Orion Nebula with your unaided eyes. This hazy smudge of light lies about 1,350 light years away in the Sword of Orion, hanging below Orion’s Belt, and is the birthplace for new generations of stars and planets – it makes an easy target for binoculars. Many stars are born in clusters such as the Pleiades and Hyades in Taurus and may take many millions of years to escape their gravitational shackles to become independent denizens of our galaxy, like the Sun.

We must look low down in the south-south-west for the first planet to become visible at nightfall. The evening star, Venus, stands higher each evening, its altitude at sunset as seen from Edinburgh climbing from 15° to 26° during January as it brightens slightly from magnitude -4.0 to -4.1. It slides westwards to set in the south-west at 18:50 on the 1st and in the west at 20:39 on the 31st after its motion takes it from Capricornus to Aquarius.

Viewed through a telescope, it shows a small gibbous disk that swells from 12 to 15 arcseconds across as its distance falls from 193 million to 165 million km. The planet’s brilliance and low altitude may lead to some UFO reports over the coming weeks, particularly when it lies below-left of the earthlit young Moon on the 26th.

Jupiter is conspicuous high in the south-east at nightfall at present, moves to the south-west by our map times and onwards to set in the west-north-west during the early hours.

Now creeping slowly eastwards on the border between Pisces and Aries, it dims from magnitude -2.6 to -2.4 as its disk shrinks from 43 to 39 arcseconds in diameter. Catch it close to the Moon on Monday and again on the 30th.

With Nasa’s Curiosity rover safely on its way to a rendezvous in August, Mars doubles in brightness from magnitude 0.2 to -0.6 and approaches from 156 million to 119 million km during January. It lies in south-eastern Leo and rises in the east less than 90 minutes after our star map times.

It is best viewed some six hours later, though, as it crosses Edinburgh’s meridian at an altitude of 40°. A telescope shows its small rust-coloured disk which grows from 9 to 12 arcseconds in diameter and has a prominent white northern polar cap. Look for Mars above the Moon on the morning of the 14th.

Our other conspicuous morning planet is Saturn which rises in the east at about 02:10 on the 1st and by 00:20 on the 31st. Brightening a little from magnitude 0.7 to 0.6, it stands a few degrees to the left of Virgo’s leading star Spica as the pair climb through the south-east to pass 25° high across Edinburgh’s meridian before dawn. At magnitude 1.0, Spica is fainter than Saturn and lies just above the last quarter Moon on the 16th morning.

Mercury rises in the south-east 92 minutes before sunrise on the 1st and is bright (magnitude -0.4) but very low down in the pre-dawn twilight over the following week or so.

The Sun tracks a welcome 5.7° northwards during January as sunrise/sunset times for Edinburgh change from 08:44/15:49 on the 1st to 08:10/16:43 on the 31st and nautical twilight shrinks in duration from 96 to 86 minutes. The Moon is at first quarter on the 1st, full on the 9th, at last quarter on the 16th, new on the 23rd and back at first quarter on the 31st.

Comet Lovejoy, discovered by an Australian amateur astronomer on 27 November, passed only 140,000 km from the Sun’s surface on 16 December. Almost all such comets are destroyed at this point but not Comet Lovejoy which seems to have emerged from its encounter with new vigour and a long tail stretching upwards in the dawn twilight for observers south of the Equator.

Finally, there is welcome news that BBC2 has scheduled a second series of Stargazing Live to be broadcast on the evenings of 16 to 18 January. Several associated local events are being planned to bring astronomy to the public across Britain, including one at the Royal Botanic Gardens Edinburgh on the 18th. Participants include the Royal Observatory, the National Museum and the Astronomical Society of Edinburgh.