This is way cooler than those chocolate filled advent calendars that you can buy at the grocery store (although arguably less yummy): The Big Picture over at The Boston Globe is doing an advent calendar to count down the days until Christmas, only instead of opening a little door to nuggets of chocolate each day, you get huge chunks of Hubble eye candy!
Each day until Christmas you can feast your eyes on a new image from the Hubble Space Telescope like today’s shown above. Hubble has produced enough images over its lifetime to fill a few thousand advent calendars. If you happened to be worried about your waistline this holiday season, forget buying a calorie-bloated advent calendar and head on over to The Big Picture for the next 24 images, which are sure to be stunning.
Little cycling cap tip to The Bad Astronomer
Nicholos. Why isn’t the object named here or any information given about this object?
The image is of course of the well-studied bipolar planetary nebula NGC 2818 or HEN 2-22 in Pyxis. This was discovered by the southern observer, James Dunlop on the 26th May 1826, and catalogued later as DUN 564. Dunlop saw it only as a cluster with a nebula. This was only one of four PNe found by him. (The CGPN (planetary nebula catalogue says the discoverer was John Herschel in 1838, but this is wrong!)
This PNe (planetary nebula) association with the cluster (NGC 2818A) has yet to be absolutely confirmed to be associated with the cluster. The cluster’s distance is though to be about 3.2 kpc, as said in the Hubble site. The PNe is most references say 2.1 kpc. As nebulae or notoriously difficult to judge distance, this will be hard to assume.
The temperature of the white dwarf nuclei is 195,000K whose mass is estimated to be slightly greater than 0.94 Solar masses