EDP Sciences
Free Access
Volume 398, Number 3, February II 2003
Page(s) L41 - L44
Section Letters
DOI https://doi.org/10.1051/0004-6361:20021878
Published online 28 January 2003

A&A 398, L41-L44 (2003)
DOI: 10.1051/0004-6361:20021878


Imaging and spectroscopy of comet C/2001 Q4 (NEAT) at 8.6 AU from the Sun

G. P. Tozzi1, H. Boehnhardt2, 3 and G. Lo Curto2

1  INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
2  European Southern Observatory ESO, Alonso de Cordova 3107, Santiago de Chile, Chile
    e-mail: hboehnha@eso.org, glocurto@eso.org
3  Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
    e-mail: hboehnha@mpia-hd.mpg.de

(Received 20 November 2002 / Accepted 19 December 2002 )

Comet C/2001 Q4 (NEAT) was observed inbound at an heliocentric distance of 8.6 AU. Broadband filter images in the visible and long slit spectroscopy in the 3500-7000 Å range was recorded. No sign of CN emission was detected and an upper limit for CN production rate of  $1.4\times10^{25}$ molecules s -1 is estimated. The color of the dust in the inner coma is very red with a spectral index of 29%/1000 Å. The radial profile of the dust coma displays steep gradients of 1.7 (inner part) to 2.4 (outer part). The af $\rho$ value, a proxy for the dust production, is measured to be 1500 cm. The coma shows a weak and short conic structure in the northern hemisphere that is interpreted as dust fan produced by an active region on the nuclear surface.

Key words: comets -- C/2001 Q4 (NEAT) -- distant activity

Offprint request: G. P. Tozzi, tozzi@arcetri.astro.it

© ESO 2003

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.