Ursid activity to peak on December 22

Nearly one week after the impressive Geminid peak of activity, another interesting meteor shower is about to undergo its maximum of activity: the Ursid (URS) meteor shower, associated to periodic comet 8P/Tuttle should reach a ZHR close to 10 on December 22, around 15 h UT.

If Ursids ZHR is 10 to 20 times less than the one of the Geminids, this is anyway a very interesting meteor shower, as it’s sometimes the source of activity outburst or enhancements that are sometimes difficult to forecast. The two main outbursts occured in 1945 and 1986, when ZHRs reached up to 50. Less intense outbursts were also observed on 2006 and 2008, when the 13,6-year period comet at the source of the shower was close to perihelion. But in 2014 and 2015, the activity zalso seems to have been enhanced, although the comete was close to aphelion.

Nothing unusual is predicted this year, and the classical maximum is predicted to happen around 15 h UT, on december 22. But it’s interesting to note that according to Jérémie Vaubaillon’s modelizations, it seems the Earth will get close to a dust trail ejected from the comet in 884 AD, and activity could thus be slightly enhanced during the maximum, as the time of the close approach is predicted to be December 22, 14 h 43 min UT.

The radiant of the Ursid meteor shower is located close to Kochab (beta Ursa Minor), and it’s thus circumpolar for most of Northern hemisphere observers. And unobservable for astronomer located Sputh of the equator. But it locates much higher in the sky at the end of the night, so observers should concentrate on the hours before dawn to catch as many meteors as possible. This year, the Moon won’t be a nuisance, as it’s a thin crescent that set early in the evening: it’s thus a good year to closely monitor the activity of this shower, which is poiorly observed due to the period it’s active, and the bad meteorological conditions that often occurs at this period of the year. So if you benefit of clear skies, please do not hesitate to osberve them and report! Thanks in advance!