Published in

American Astronomical Society, Astrophysical Journal, 2(490), p. L199-L202, 1997

DOI: 10.1086/311040

Links

Tools

Export citation

Search in Google Scholar

Neutral sodium from comet Hale-Bopp: a third type of tail

Journal article published in 1997 by G.(1) Cremonese, H.(2) Boehnhardt, H. Böhnhardt, J.(3) Crovisier, H. Rauer, A.(4) Fitzsimmons, M.(5) Fulle ORCID, J.(6) Licandro, D.(7) L Pollacco, G. P.(8) Tozzi, G. P.(8) Tozzi, R. M.(9) West, R. M.(9) West
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Green circle
Published version: archiving allowed
Upload
Policy details
Data provided by SHERPA/RoMEO

Abstract

We report on the discovery and analysis of a striking neutral sodium gas tail associated with comet C/1995 O1 Hale-Bopp. Sodium D-line emission has been observed at heliocentric distance r<= 1.4 AUin some long-period comets and the presence of neutral sodium in the tailward direction of a few bright comets has been noted, but the extent, and in particular the source, has never been clear. Here we describe the first observations and analysis of a neutral sodium gas tail on comet Hale-Bopp, entirely different from the previously known ion and dust tails. We show that the observed characteristics of this third type of tail are consistend with it being produced by radiation pressure due to resonance fluorescence of sodium atoms and that the lifetime for photoionization is consistent with recent theoretical calculations.