TL;DR: A white dwarf supernova was just discovered in the nearby starburst galaxy M82. Details are still coming in, but this will be an excellent chance to study this type of system up-close, plus it may come within visual range of your backyard telescope. And here it is, courtesy of @NickAstronomer

Okay, NOW I’m awake. A longtime source of news about transient phenomena in the sky, the Astronomer’s Telegram, now has a Twitter account which posted this brief by Cao, et al. I’ll quote some important bits:

At UT 2014 Jan 22.305, we obtained a spectrum of PSN_J09554214+6940260 (discoverer: S. J. Fossey) … We classify this as a Type Ia supernova … The best superfit match is SN2002bo at -14d… Panchromatic follow-up is encouraged.

Okay, let’s break this down a bit. First of all, our long-monikered supernova has been given the spectral classification of Type 1a. Generally this means that the spectrum doesn’t show hydrogen but does show ionized silicon early on. What that really means is that the supernova occurred as the result of a white dwarf in a binary system taking on way too much material and blowing itself apart. This is different from a core-collapse supernova, in which a massive star runs out of nuclear fuel and blows itself apart.

Type 1a supernovae have distinguished themselves as standard candles in astronomy. That means the luminosity of these explosions is well known and can be figured out from measuring the light curve, or brightness with time. Get the actual luminosity of the supernova, and you can measure its distance. This makes such supernovae important in the “distance ladder” of astronomy; and they were key in the discovery of the accelerating expansion of the Universe due to dark energy.

via Supernova Alert! | CosmoQuest Blog.

Saturn and the waning crescent Moon rising to the SE at about 4 AM local on January 25th, 2014. Created using Stellarium.

Mark your calendars: the first in a series of interesting occultations of Saturn by the Moon for 2014 starts this weekend.

The year 2014 features 11 occultations of the planet Saturn by the Moon, and there are 23 total for 2014 of every planet except Neptune and Jupiter.

An occultation occurs when one foreground celestial object completely obscures another. Technically, a total solar eclipse is an occultation of the Sun by the Moon, although it’s never referred to as such. The term finds modern usage mainly for the blocking of stars and planets by the Moon. Very occasionally, an asteroid or planet can occult a distant star as well.

And yes, the modern astronomical term “occultation” traces its hoary roots back to the days when astronomy was intertwined with the pseudoscience of astrology.  To this day, the term still makes some folks wonder if astronomers are secretly casting horoscopes. Trust us, you’re still on a solid astronomical footing to use the term “occultation.”

via The Moon Occults Saturn in the Dawn this Weekend.

The Rosetta spacecraft “woke up” after a record 957 days of hibernation. The first communication from the spacecraft arrived at the European Space Operations Center in Darmstadt, Germany, at 7:18 p.m. local time (1:18 p.m. EST / 10:18 a.m. PST). The signal was received by a ground station at the Goldstone, Calif., complex of NASA’s Deep Space Network.

Rosetta, heading toward comet 67P/Churyumov-Gerasimenko, is an international mission spearheaded by the European Space Agency with support and instruments provided by NASA.

Comets are among the most beautiful and least understood nomads of the night sky. To date, half a dozen of these most heavenly of heavenly bodies have been visited by spacecraft in an attempt to unlock their secrets. All these missions have had one thing in common: the high-speed flyby. Like two ships passing in the night (or one ship and one icy dirtball), they screamed past each other at hyper velocity — providing valuable insight, but fleeting glimpses, into the life of a comet. That is, until Rosetta.

NASA is participating in the European Space Agency’s Rosetta mission, whose goal is to observe one such space-bound icy dirt ball from up close — for months on end. The spacecraft, festooned with 25 instruments between its lander and orbiter (including three from NASA), is programmed to “wake up” from hibernation on Jan. 20. After a check-out period, it will monitor comet 67P/Churyumov-Gerasimenko as it makes its nosedive into, and then climb out of, the inner solar system. Over 16 months, during which old 67P is expected to transform from a small, frozen world into a roiling mass of ice and dust, complete with surface eruptions, mini-earthquakes, basketball-sized, fluffy ice particles and spewing jets of carbon dioxide and cyanide.

via Rosetta: To Chase a Comet | NASA.