Ursids - radio results

When observed by radio methods, the Ursids produce a brief peak of activity which generally only rises above the background rate for a few hours. The following year's Ursid radio results have been analysed.

2006 Ursids - radio results

The following information is based on a small sample of results taken from the contents of Meteor Observation Bulletin No.161.

Radio Ursids 2006 Peak 

The data below suggests that the 2006 Ursid produced significant activity between 04:00 UT on the 22nd December 2006 (270.059°) and 10:00 UT on the 23rd December 2006 (271.332°). The activity profile, for the 2006 Ursids, appears complex, possibly with multiple peaks. Consequently it isn't possible to give a time for a single 2006 Ursid peak. However, the mean value of start and end of the 2006 Ursids, noted previously, is 270.6955° and very close to the accepted value of the shower's maximum solar longitude of 270.7°.

Enric Fraile Algeciras (Spain)

Data

Analysis

Ursid activity rose above the background from 06:00 UT on the 22nd December 2006  (270.144°) and fell below the background by 10:00UT on the 23rd December 2007 (271.332°). SBV analysis suggested a number of possible fits to the stream and so no precise figures are quoted.

Jeff Brower (Canada)

Data

Analysis

The 2006 Ursids appear to have been particularly well observed by Jeff. 

T_max = 2006 December 22, 19:41 UT +1.7 h , width a = 1.0, b = 1.0

Peak solar longitude (J2000) = 270.725° + 0.07°

Esrange SkiyMet (Sweden)

Data

Analysis

Ursid activity rose above the background from 06:00 UT on the 22nd December 2006  (270.144°) and fell below the background by 08:00UT on the 23rd December 2007 (271.247°). SBV analysis suggested a number of possible fits to the stream and so no precise figures are quoted.

Dave Swan (England)

Data

Analysis

Ursid activity rose above the background from 06:00 UT on the 22nd December 2006  (270.144°) and fell below the background by 04:00UT on the 23rd December 2007 (271.077°). SBV analysis suggested a number of possible fits to the stream and so no precise figures are quoted.

Felix Verbelen (Belgium)

Data

Analysis

Ursid activity rose above the background from 04:00 UT on the 22nd December 2006  (270.059°) and fell below the background by 08:00UT on the 23rd December 2007 (271.247°). SBV analysis suggested a number of possible fits to the stream and so no precise figures are quoted.

2005 Ursids - radio results

The following information is based on a small sample of results taken from the contents of Meteor Observation Bulletin No.149.

Radio Ursids 2005 Peak Time (UT)

The average time for the radio Ursids 2005 is calculated as 22nd December 2005, 12:53 UT.

Radio Ursids 2005 Peak Solar Longitude (J2000)

The average solar longitude for the radio Ursids 2005 is calculated as 270.695°.

David Entwistle (England)

Data

Analysis

T_max = 2005 December 22, 10:54 UT +3.9 h , width a = 10, b = 10

Peak solar longitude (J2000) = 270.611° + 0.163°

Dave Swan (England)

Data

Analysis

T_max = 2005 December 22, 14:52 UT +4.3 h , width a = 2.8, b = 2.8

Peak solar longitude (J2000) = 270.780° + 0.182°

Acknowledgements

I am grateful to the following persons for their efforts in recording meteor counts: Enric Fraile Algeciras (Spain), Orlando Benitez Sanchez (Gran Canaria), Michael Boschat (Canada), Alessandro and Giuseppe Candolini (Italy), Walter Boschin (Spain), Jeff Brower (Canada), Gaspard De Wilde (Belgium), David Entwistle (England), Pierre De Groote (Belgium), Patrice Guerin (France), Peter Knol (The Netherlands), Stan Nelson (USA), Sadao Okamoto (Japan), Valter Gennoro (Italy), Mike Otte (USA), Jean-Louis Rault (France), Andy Smith (England), Dave Swan (England), Istvan Tepliczky (Hungary), Felix Verbelen (Belgium).

Special thanks go to Professor Nick Mitchell and the University of Bath, Dynamics of the Mesosphere & Lower Thermosphere group for allowing access to the SkiyMet data.

I'm also especially grateful to Christian Steyaert for his efforts in collecting, collating and distributing the rmobs data and to Pierre Terrier for his work in supporting this effort.

References

* 'A numerical method to aid in the combined determination of stream activity and Observability Function', by Christian Steyaert, Jeffrey Brower, and Felix Verbelen. Taken from WGN, the Journal of the IMO 34:3 (2006).