Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth - Ptolemy
Quite the weirdest (astronomy-speaking) thing I've heard about all year has to be the discovery of an extragalactic planet in our own galaxy. The gas giant orbits the dying star HIP 13044, so the planet has been dubbed HIP 13044 b. Of all the extrasolar planets detected so far, HIP 13044 b is unique in that it began life outside our galaxy, probably in a dwarf galaxy which wandered too near the Milky Way and ended up being absorbed in what astronomers call 'galactic cannibalism'. When I mentioned it to my teenage son, his first question was: How do they know? which is what I was wondering too, but the astronomers know HIP 13044 belongs to a group of stars called the 'Helmi stream' which are known to have originated in a different, smaller galaxy. One of the planet's discoverers, Rainer Klement of the Max Planck Institute for Astronomy in Heidelberg, Germany, said: For the first time, astronomers have detected a planetary system in a stellar stream of extragalactic origin. This cosmic merger has brought an extragalactic planet within our reach. Although 'within our reach' is on a cosmic time/distance scale (HIP 13044 lies 2,000 light years1 away) it's still an exciting discovery, as it's proof that solar systems can survive galactic encounters known as 'cosmic trainwrecks', so there's hope for the Earth yet. The Milky Way and Andromeda galaxies are on a collision course, and we know the galaxies will be torn apart during their titanic struggle, before their eventual merger. But at least we now know that there's a possibility that our Solar System may remain intact!
Christmas Scenes in Space
Most people complain about the cold of winter, but we get off lightly compared to the weather on say, Enceladus, a moon of Saturn, where ice geysers erupt at temperatures of −200°C. Brr! Setting the wintry scene, how about a snowflake in space? That cosmic feature is an open cluster with nebulosity nestled beyond the constellation of Monoceros 'the Unicorn'. Who likes Christmas trees? There's something similar to our traditional Christmas symbol, also in Monoceros — a diffuse nebula catalogued NGC 2264 which features a star cluster called, funnily enough, the Christmas Tree Cluster. Whatever you are doing over the festive season, alone or in company, celebrating or can't-wait-till-it's-over, I wish you well, be happy, and please join me in a toast to absent friends. Here's to 2011, which has an exciting start in the world of astronomy — I've referenced the dates in a sneak preview for you.
December Diary Dates
- 05: New Moon
- 13/14: Geminids meteor shower peak
- 14: Danish astronomer Tycho Brahe was born on 14 December, 1546
- mid-month onwards: Saturn rises at 2am with Venus following at around 4am (direction E.S.E.)
- 21: Full Moon (The Cold Moon, Long Nights Moon, Moon before Yule)
- 21: Total lunar eclipse (visible from Europe, east Asia, Australia, Pacific, Americas)
- 21: Northern Hemisphere Winter Solstice 23:38pm/Summer Solstice (Southern Hemisphere)
- 22: Ursids meteor shower peak
- 25: Christmas: Have you ever wondered about what the Star of Bethlehem could possibly have been?
- 31: Hogmanay/New Year's Eve, watch for the Moon and Venus lining up to dance the old year out
Due to the extended Post Christmas break, here are the early January diary dates:
January 2011 Diary Dates
- 03/04: Quadrantids meteor shower peak
- 04: New Moon
- 04: Partial solar eclipse visible in most parts of Europe, Asia and northern Africa
- 04: Uranus just north of Jupiter
- 19: Full Moon (the Wolf Moon, Old Moon, Ice Moon, or the Moon after Yule)
Chat about your celestial observances at the H2G2 Astronomy Society. Comment on anything in this edition of Babe Among the Stars by starting a new conversation below.