14:15 〜 14:30
[PPS03-15] 次世代サンプルリターンターゲット289P/Blanpainを起源とする「ほうおう座流星群」の分光観測
キーワード：ほうおう座流星群、ブランパン彗星、ふたご座流星群、はやぶさ
The Jupiter-family comet, 289P/Blanpain, has a red reflection spectrum similar to that of D-type asteroids and is considered to originate from the distant region of the solar system. The 289/PBlanpain is a candidate object for JAXA's next generation small body sample return mission in the solar system. The Phoenicid meteor shower and its parent body, 289P/Blanpain, exemplify the complex relationship between cometary disintegration and meteor shower production. This system provides a unique opportunity to study both historical cometary breakup and the resulting meteoroid stream evolution over two centuries. Comet 289P/Blanpain, discovered in 1819 by Jean-Jacques Blanpain, was subsequently lost for approximately 200 years. Its rediscovery in 2003 as the asteroid 2003 WY25 establishing that the object had evolved dramatically since its initial discovery, displaying minimal cometary activity. The connection between 289P/Blanpain and the Phoenicids was definitively established by Jenniskens and Lyytinen (2005), who demonstrated through numerical modeling of cometary dust trails that the 1819/1820 breakup event of the Blanpain produced the meteoroids responsible for the short but intense Phoenicids outburst observed in 1956. This connection was further strengthened by subsequent investigations by Sato and Watanabe (2010).
The 1956 Phoenicids outburst, with a Zenithal Hourly Rate (ZHR) of approximately 100 meteors, represented one of the most dramatic manifestations of this disintegration event. Weiss (1958) provided early documentation of this phenomenon, with McBeath (2003) and Watanabe et al. (2005) offering more detailed retrospective analyses that confirmed the connection to Blanpain's earlier breakup. A second significant outburst in 2014, documented by Fujiwara et al. (2017), produced a ZHR of approximately 33±4, demonstrating the continued activity of the meteoroid stream over 150 years after the initial breakup event. This outburst validated predictions by Sato and Watanabe (2014).
The comet itself continues to show signs of instability, as evidenced by its remarkable outburst in July 2013. This event, occurring at 3.9 AU from the Sun, featured a 9-magnitude brightness increase - making it one of the largest comet outbursts ever observed. Ye et al. (2020) determined that this outburst produced approximately 108 kg of dust, representing about 1% of the comet's nucleus mass. Their analysis suggested that crystallization of amorphous water ice, triggered by a spin-up disruption of the nucleus, was the most likely mechanism.
The Phoenicids are characterized by an unusually low atmospheric entry velocity, approximately 11 km/s. This property makes them one of the slowest meteor showers and results in distinctive atmospheric behavior, including longer visible durations and often brighter meteors. Based on the forecast for the Phoenicid meteor shower, which was ejected in 1866, will reach its maximum around mid-November, 2024, we called for a spectroscopic observation campaign around this maximum period. Spectroscopic observations were carried out at the Ishigakijima Observatory of the National Astronomical Observatory of Japan from November 13 to 17, 2024. In the campaign observation, two spectra were successfully captured from our Ishigakijima Observatory and from Saitama Prefecture (Mr. Takashi Sekiguchi, Nippon Meteor Society (NMS)), respectively.
In order to discuss the cometary activity, Na/Mg/Fe emission intensity ratios of Phoenicids meteoroids will be shown and compared with that of the Geminid meteor shower derived from the active asteroid Phaethon, the exploration target of JAXA's DESTINY+.
The 1956 Phoenicids outburst, with a Zenithal Hourly Rate (ZHR) of approximately 100 meteors, represented one of the most dramatic manifestations of this disintegration event. Weiss (1958) provided early documentation of this phenomenon, with McBeath (2003) and Watanabe et al. (2005) offering more detailed retrospective analyses that confirmed the connection to Blanpain's earlier breakup. A second significant outburst in 2014, documented by Fujiwara et al. (2017), produced a ZHR of approximately 33±4, demonstrating the continued activity of the meteoroid stream over 150 years after the initial breakup event. This outburst validated predictions by Sato and Watanabe (2014).
The comet itself continues to show signs of instability, as evidenced by its remarkable outburst in July 2013. This event, occurring at 3.9 AU from the Sun, featured a 9-magnitude brightness increase - making it one of the largest comet outbursts ever observed. Ye et al. (2020) determined that this outburst produced approximately 108 kg of dust, representing about 1% of the comet's nucleus mass. Their analysis suggested that crystallization of amorphous water ice, triggered by a spin-up disruption of the nucleus, was the most likely mechanism.
The Phoenicids are characterized by an unusually low atmospheric entry velocity, approximately 11 km/s. This property makes them one of the slowest meteor showers and results in distinctive atmospheric behavior, including longer visible durations and often brighter meteors. Based on the forecast for the Phoenicid meteor shower, which was ejected in 1866, will reach its maximum around mid-November, 2024, we called for a spectroscopic observation campaign around this maximum period. Spectroscopic observations were carried out at the Ishigakijima Observatory of the National Astronomical Observatory of Japan from November 13 to 17, 2024. In the campaign observation, two spectra were successfully captured from our Ishigakijima Observatory and from Saitama Prefecture (Mr. Takashi Sekiguchi, Nippon Meteor Society (NMS)), respectively.
In order to discuss the cometary activity, Na/Mg/Fe emission intensity ratios of Phoenicids meteoroids will be shown and compared with that of the Geminid meteor shower derived from the active asteroid Phaethon, the exploration target of JAXA's DESTINY+.