Search for OH(A–X) and detection of N þ 2 (B–X) in ultraviolet meteor spectrum Shinsuke Abe a, * , Noboru Ebizuka b , Hajime Yano c , Jun-ichi Watanabe d , Jir ˇı ´ Borovic ˇka e a Department of Earth and Planetary Sciences, Faculty of Science, Kobe University, Nada, Kobe 657-8501, Japan b Department of Physics, Konan University/RIKEN, Higashi-Nada, Kobe 658-8501, Japan c Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan d National Astronomical Observatory of Japan, National Institutes of Natural Sciences, NINS, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan e Astronomical Institute of the Academy of Sciences, 298 Fricova, Ondrejov 25165, Czech Republic Received 4 October 2004; received in revised form 16 March 2007; accepted 21 March 2007 Abstract An ultraviolet–visible spectrum between 300 and 450 nm of a cometary meteoroid originated from 55P/Tempel-Tuttle was investi- gated. The spectroscopy was carried out an intensified high definition TV camera with a slit-less reflection grating during the 2001 Leonid meteor shower over Japan. A best fit calculation mixed with atoms and molecules confirmed the first discovery of N þ 2 B 2 R þ u ! X 2 R þ g bands in the UV meteor spectrum. N þ 2 temperature was estimated to 10,000 K with a low number density of 1.55 · 10 5 cm 3 . We also discuss the possibility that enhanced emissions in a meteor and a train around 310 nm are caused by the band head of OH A 2 R + ! X 2 P. Since cometary dust may have contributed organics and water to the Earth from its early period until now, OH A–X (0, 0) must be investigated. Ó 2007 Published by Elsevier Ltd on behalf of COSPAR. Keywords: Astrobiology; Comets: individual(55P/Tempel-Tuttle); Interplanetary medium; Meteors; Meteoroids; Molecular processes 1. Introduction Spectroscopic observations of meteors reveal not only chemical composition of the cometary meteoroids but also emission processes of hypervelocity impacts in the atmo- sphere, which are difficult to reproduce in laboratory experiments at present. Leonid meteoroids which corre- spond to cometary grains from the comet 55P/Tempel-Tut- tle have produced the best meteor shower for its high incident velocity at 72 km s 1 among known annual meteor showers and bright flux of its meteors as 10,000 h 1 . Of particular interest is the question whether meteoroids could have delivered organics and water to the early Earth Jenniskens et al. (2000). Rietmeijer (2002) suggested that the survival of meteoritic compounds would be feasible even at high entry velocities. According to this author, cometary meteoroids are aggregates that might include the precursors of the Interplanetary Dust Particles (IDPs) collected in the upper atmosphere. To determine whether large cometary grains contain mineral water or trapped water in any forms, it is necessary to confirm the presence of OH A 2 R + ! X 2 P emission around the wavelength of 310 nm. Harvey (1977), Abe et al. (2003a, 2005) and Jen- niskens et al. (2002) reported an excess of emission at 310 nm. Here we report the discovery of N þ 2 B 2 R þ u ! X 2 R þ g (N þ 2 ð1Þ) in the wavelength of 320–450 nm meteor emis- sion from a Leonid meteoroid through the investigation of OH A–X (0, 0) band. The N þ 2 ð1Þ plasma emission in meteors has been argued by Millman et al. (1971) and Mukhamednazarov and Smirnov (1977). Meanwhile Jenniskens et al. (2004a) found a N þ 2 A 2 P u ! X 2 R þ g Meinel 0273-1177/$30 Ó 2007 Published by Elsevier Ltd on behalf of COSPAR. doi:10.1016/j.asr.2007.03.051 * Corresponding author. E-mail addresses: avell@kobe-u.ac.jp (S. Abe), ebizuka@riken.jp (N. Ebizuka), yano.hajime@jaxa.jp (H. Yano), jun.watanabe@nao.ac.jp (J.-i. Watanabe), borovic@asu.cas.cz (J. Borovic ˇka). www.elsevier.com/locate/asr Advances in Space Research 39 (2007) 538–543