SuprimeCam Observation of Sporadic Meteors during Perseids 2004

Authors: M.Iye, M.Tanaka, M.Yanagisawa, N.Ebizuka, K.Ohnishi, C.Hirose,
N.Asami, Y.Komiyama, H.Furusawa

(Submitted on 26 Apr 2007)

Abstract: We report the serendipitous findings of 13 faint meteors and 44
artificial space objects by Subaru SuprimeCam imaging observations during
11-16 August 2004. The meteors, at about 100km altitude, and artificial
satellites/debris in orbit, at 500km altitude or higher, were clearly
discriminated by their apparent defocused image sizes. CCD photometry of the
13 meteors, including 1 Perseid, 1 Aquarid, and 11 sporadic meteors, was
performed. We defined a peak video-rate magnitude by comparing the
integrated photon counts from the brightest portion of the track traversed
within 33ms to those from a 0-mag star during the same time duration. This
definition gives magnitudes in the range 4.0< V_{vr} <6.4 and 4.1<
I_{vr}<5.9 for these 13 meteors. The corresponding magnitude for virtual
naked-eye observers could be somewhat fainter especially for the V-band
observation, in which the [OI] 5577 line lasting about 1 sec as an afterglow
could contribute to the integrated flux of the present 5-10 min CCD
exposures. Although the spatial resolution is insufficient to resolve the
source size of anything smaller than about 1 m, we developed a new estimate
of the collisionally excited column diameter of these meteors. A diameter as
small as a few mm was derived from their collisionally excited photon rates,
meteor speed, and the volume density of the oxygen atoms at the 100km
altitude. The actual column diameter of the radiating zone, however, could
be as large as few 100m because the excited atoms travel that distance
before they emit forbidden lines in 0.7 sec of its average lifetime. Among
the 44 artificial space objects, we confirmed that 17 were cataloged
satellites/space debris.

Comments:

14 pages, 13 figures, 5 tables, submitted to PASJ

Subjects:

Astrophysics (astro-ph)

Cite as:

arXiv:0704.3491v1 [astro-ph]

Submission history

From: Masanori Iye Prof. [view email]

[v1] Thu, 26 Apr 2007 07:59:24 GMT (809kb)