Evropská jižní observatoř

Kategorie: Sluneční soustava, Zpět na celou fotogalerii.

Popis (v anglickém jazyce):

These two photos from the ESO La Silla observatory
show the individual nuclei of comet Shoemaker-Levy 9,
now headed for collision with Jupiter on 16 - 22 July
1994.

The wide-field photo (below, left) was obtained by
Klaus Jockers and Galina Chernova
(Max-Planck-Institute fur Aeronomie, Katlenburg,
Lindau, Germany) on May 1, 1994. For this 5 min
exposure in red light they used a CCD camera at the
MPIfAe/Hoher List focal reducer at the ESO 1-metre
telescope. The entire nuclear train (the "string of
pearls") is very well seen, together with the
sunlight-reflecting dust from the nuclei, all on one
side. On this date, the comet was 654 million km from
the Earth and the angular extension of the train was
about 5.3 arcmin, corresponding to a projected length
of just over 1 million km.

A 15 min CCD image was obtained for astrometric
purposes on May 11, 1994, by Jean-Francois Claeskens
at the Danish 1.5 m telescope at La Silla; it is here
reproduced in close-up to show well the individual
nuclei, in particular the fainter ones. The bright
object to the upper right is a 10th mag star. Note
that the stars in the field are somewhat trailed,
since the telescope was set to follow the motion of
the comet. The first nucleus to hit Jupiter will be
"A", here seen 42 mm from the left edge and 33 mm
below the upper edge of the large picture. The last
is "W", 43 mm above the lower edge and 9 mm from
the right edge. The comet was 657 million km from the
Earth and the train was somewhat longer, 5.8 arcmin,
i.e. the projected length was now 1.1 million km.

Technical information: Wide-Field: pixel size 1.5
arcsec; scale on photo: 5.1 arcsec/mm; field size:
12.2 x 6.6 arcmin; 5 min exposure; gunn-r
filtre. Close-Up: pixel size 0.38 arcsec; scale on
photo: 1.3 arcsec/mm; field size: 6.4 x 4.4 arcmin;
15 min exposure; V-filtre. On both photos, North is
up and East is to the left; both were obtained during
moderate seeing conditions.

Odkaz na další informace na www.eso.org (stránka v AJ)