Sky Notes for December 2013 with James Abbott #stargazing
The Winter Solstice marks the start of the days lengthening again and takes place on December 21st at just after 5pm GMT. From our latitude mid-winter brings 8 hours of daylight, 12 hours of proper night and 4 hours of varying degrees of twilight.
The Moon is Full on December 17th so the Christmas week will see the winter stars at their best. By late evening all the winter constellations are on show, with Jupiter high up in Gemini and due South soon after midnight by the end of the month. At mag -2.7 it will be brighter than any of the stars. The quality of images of Jupiter and its satellites continues to advance with this remarkable capture of detail on Ganymede by Leo Aerts:
Venus is visible throughout the month, but remains rather low in the South West as it gets dark in the evening. The best chances of viewing Venus will be in early December between 5pm and 6pm.
The Geminid meteors are now the most active regular shower each year. They peak on the night of the 13th/14th and meteors should be visible all night. However there is some Moon interference this year which will mean the fainter meteors will be difficult for evening observers. One way of boosting the chances of success are to stand somewhere that is shielded from direct Moonlight or view in the pre-dawn hours when the Moon has set.
Throughout the first and last weeks of December when the Moon is out of the way, it will be worth keeping a watch on the Northern skies during the late evening period to see if the elusive Northern Lights appear. The Sun is currently the most active it has been in many years, raising the chances of a big display that might get down to our latitude.
Comet ISON brightened significantly in mid-November and was seen as a binocular object at mag +5 briefly from mid-Essex pre-dawn. However, professional observations of molecular emission lines in the days up to November 25th showed rapid fading. Parent molecules have a very short lifetime as they are quickly broken up by solar radiation and so are a good approximation of the current activity level of a comet nucleus. This evidence, together with other activity noted before November 20th suggests the nucleus may have already disrupted, which will mean the “Comet of the Century” will not be. But whether it dazzles or fizzles, ISON is totally unpredictable and observations will help inform us more about these ancient objects.
James Abbott is an astronomer, NEAS member and CfDS Regional Information Officer.
Posted on 7 December, 2013, in Astronomy News, Observing News, Popular Science, Stargazing and tagged aurora, ganymede, geminids, ison, meteor shower, meteors, northern lights, venus, Winter Solstice. Bookmark the permalink. Comments Off on Sky Notes for December 2013 with James Abbott #stargazing.