A -4 mag Ursid fireball captured on December 22nd, 2016. Copyright: Kai Frode Gaarder
A -4 mag Ursid fireball captured on December 22nd, 2016. Copyright: Kai Frode Gaarder

Ursids meteor shower is the last one to be active of the year. The expected ZHR during the maximum of Ursids activity period is most of the time ranging around 10. But it can also reach 50 during expected or unexpected outbursts. In 2016, according to the IMO Meteor Shower Calendar, the theoritical maximum was expected to occur on December 22nd, 9h UT, with usual ZHR levels (close to 10). Jérémie Vaubaillon also suspected some potential additional activity enhancements to occur on December 23rd and 24th, around 0h UT. But from first analysis analysis of RMOJ and RMOB data, radio observers recorded a Ursids activity enhancement on December 22nd, around 10h 30min UT, which fits with the classical theoritical predicted peak, but with higher than usual activity levels.

2016 Ursids activity profile as calculated by Hiroshi Ogawa, from data coming from RMOJ and RMOB databases. Credit: The International Project for Radio Meteor Observations – Hiroshi Ogawa
2016 Ursids activity profile as calculated by Hiroshi Ogawa, from data coming from RMOJ and RMOB databases. Credit: The International Project for Radio Meteor Observations – Hiroshi Ogawa

From Hiroshi Ogawa (Nippon Meteor Society) analysis, the radio activity features a defined peak, not as enhanced as the one observed during the 2014 Ursids return (when visual ZHR reached 35), but which seems to indicate that the activity of the meteor shower was above usual, potentially leading to a visual estimates ZHR close to 20, according to Hirofumi Sugimoto. Visual observations can hardly confirm it yet, as no visual observating reports have been submitted to the IMO for this period so far. But if anyone have been observing tat that time, his data are of high interest to confirm (or not, in case this radio outburst was associated to very small meteoroids) this enhanced Ursid activity!

UPDATE (12/01/2016): Felix Verbelen shared his radio recordings of the 2016 Ursids, as observed from his station of Kampenhout. It clearly shows the activity peak previously evocated int he article. From Mikhail Maslov, this activity enhancement could be liked to the 1076 dust trail of 8P/Tuttle.

Hourly counts of radio reflexions recorded by Felix Verbelen from his station in Kampnhout. Credit: Felix Verbelen

Hourly counts of radio reflexions recorded by Felix Verbelen from his station in Kampnhout. Credit: Felix Verbelen

2 comments

  • The predictions were well published, and I wanted to go see the Ursids, but was prevented by clouds in the central United States. The clouds were also present for the morning of January 3, too, which was unfortunate since the Quadrantid peak was likewise relatively well-placed longitudinally for the area this year. Thwarted by winter low clouds!

    Reply to Pete Kozich

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