Detection of Phoenicids meteor shower in 2014 *M. Sato (Kawasaki Municipal Science Museum), J. Watanabe, C. Tsuchiya (National Astronomical Observatory of Japan), A. V. Moorhead (NASA Meteoroid Environment Office, Marshall Space Flight Center), D. E. Moser (Jacobs, ESSSA Group, Marshall Space Flight Center), P. G. Brown (Department of Physics and Astronomy, The University of Western Ontario), W. J. Cooke (NASA Meteoroid Environment Office, Marshall Space Flight Center)

About Dr. Junji Nakamura He observed strong storm of Phoenicids in 1956. Photo in 1959 at the Antarctic

About Dr. Junji Nakamura He observed strong storm of Phoenicids in 1956. Sato Watanabe Nakamura Photo in 1959 at the Antarctic Photo in 2014 at La Palma He became only one person who watched Phoenicids twice.

Phoenicids was a mysterious shower ! (until 10 years ago) Background : Phoenicids was a mysterious shower ! (until 10 years ago) The great appearance was only once. Dec. 5, 1956, HR max = 300. (Nakamura & Huruhata 1957) The parent body was not identified. The candidate parent body : D/1819 W1 (Blanpain) But it was not confirmed. This comet was observed only once in 1819. Its orbit was not accurate.

Candidate object was re-discovered. 2003 WY25 = D/1819 W1 ( = 289P/ Blanpain) Foglia et al. 2005 (IAUC No.8485) Simulating by the dust trail model became possible. We tried a elucidation and a prediction of Phoenicids. Watanabe, Sato & Kasuga 2005 / Sato & Watanabe 2010.

Elucidation of Outburst in 1956 HR=300 Outburst should have been caused by a bundle of the trails formed from the late 18th through the early 19th centuries.

Forecast of shower in 2014 The trails formed from the early 20th centuries approach to the earth. However, the cometary activity of the parents in those days was not known.

Data of dust trails The peak time was expected about 0h (UT) on December 2.

Radiant point in 2014 The Radiant point was located in Sculptor. The position moved to the north from that time of 1956.

The appropriate site for observation on peak time Around of the Atlantic (But there are few locations.) Astronomical Twilight The image from radiants direction at 0:00 (UT) on December 2, 2014

Observed Results

Video network Observation results : All Sky Fireball Network of NASA (15 video cameras) SOMN (Southern Ontario Meteor Network) (11 video cameras) 5 meteors of Phoenicids were observed on December 1 – 2.

Data of detected meteors by NASA & SOMN Q* : convergence angle, Each 2nd line : Corresponding uncertainties. The observed height of meteors was very low. (about 90 - 70 km) It might be because that its velocity was so slow. (about 10 km/s)

Radiants of Phoenicids (by Video) The dispersion of radiant points was slightly large. ( I comment on this later.)

Radar observation Observation results : Canadian Meteor Orbit Radar (CMOR) 14 candidate meteors of Phoenicids were found on December 1 – 3.

Radiants of Phoenicids (Radar & Video) Radar (CMOR) Video The dispersion of radiant points by radar was larger than one by Video.

Radiants (After correction) The correction effect of the earth motion Radiants (CMOR) Radiants (After correction) (Tuchiya 2016) The correction of the earth motion makes the dispersion smaller. Pleas see the poster by Tsuchiya. (Poster No.24)

Visual observation Observation results : La Palma (Canary Islands in Spain) The Observatorio del Roque de los Muchachos (ORM) Instituto de Astrofisica de Canarias (IAC) We observed only for about 2 hours because of bad weather. 10 candidate meteors of Phoenicids were observed for 2 hours on Dec. 2.

Data of visual observation at La Palma By Tomoko sato The middle scale appearance was observed. The value of ZHR was about 10 - 30.

Radio observation Observation results : Radio forward-meteor-scatter counts Data was provided by H. Sugimoto. His data was obtained in 5 locations in Japan and 22 locations in Europe. ZHR was estmimated about 20-30 at 21-24h on Dec 1. (Sugimoto 2014, http://www5f.biglobe.ne.jp/~hro/Flash/2014/PHO/index.htm)

Time valuation of ZHR (Radio & Visual) Peak? It looks like the peak.

All results of Phoenicids in 2014 The activity was not strong. Gentle peak? It might be a gentle peak, It was uncertain.

Rough simulation in 2014 Max : ZHR = 130 @0:06 (UT) This difference is equivalent to the difference of the activity of the parent.

Transition of comet 289P/Blanpain 1800 1819 Parent comet was observed. (Discovery) Comet was active. 1850 1956 Strong Storm. 1900 ? 1909 -1930 No observation. Cometary activity might be weak. 1950 2000 2003 - Like an asteroid. (Re-discovery) Sometimes, a faint coma / a faint tail. Cometary activity became very faint. 2014 Low shower.

Conclusions : Phoenicids meteor shower would be expected in 2014 by our simulation. Actually, Phoenicids meteors were detected by several observations. It seemed that the peak time was consistent with the expected time based on our simulation. But it was uncertain. The cometary activity of parent in early 20th century might be estimated from this observation, it was so weak.

Detection of Phoenicids meteor shower in 2014 Meteoroids 2016 in ESTEC End Detection of Phoenicids meteor shower in 2014 Meteoroids 2016 in ESTEC