Evidence for fresh frost layer on the bare nucleus of comet Hale-Bopp at 32 AU distance

Gyula M. Szabó, László L. Kiss, A. Pál, C. Kiss, Krisztián Sárneczky, Attila Juhász, Michiel R. Hogerheijde

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already inactive state of the nucleus. The albedo has been found to be surprisingly large (8.1% ± 0.9%), which exceeds the value known for any other comets. With re-reduction of archive Hubble Space Telescope images from 1995 and 1996, we confirm that the pre-perihelion albedo resembled that of an ordinary comet and was smaller by a factor of two than the post-activity albedo. Our further observations with the Very Large Telescope also confirmed that the albedo increased significantly by the end of the activity. We explain these observations by proposing gravitational redeposition of icy grains toward the end of the activity. This is plausible for such a massive body in a cold environment, where gas velocity is lowered to the range of the escape velocity. These observations also show that giant comets are not just the upscaled versions of the comets we know but can be affected by processes that are yet to be fully identified.

Original languageEnglish
Article number8
JournalAstrophysical Journal
Volume761
Issue number1
DOIs
Publication statusPublished - Dec 10 2012

Fingerprint

Hale-Bopp comet
Hale-Bopp
frost
comets
comet
albedo
nuclei
sun
escape velocity
redeposition
Hubble Space Telescope
observatories
telescopes
observatory
gases

Keywords

  • comets: general
  • comets: individual: C/1995 O1 (Hale-Bopp)
  • Oort Cloud

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Evidence for fresh frost layer on the bare nucleus of comet Hale-Bopp at 32 AU distance. / Szabó, Gyula M.; Kiss, László L.; Pál, A.; Kiss, C.; Sárneczky, Krisztián; Juhász, Attila; Hogerheijde, Michiel R.

In: Astrophysical Journal, Vol. 761, No. 1, 8, 10.12.2012.

Research output: Contribution to journalArticle

Szabó, Gyula M. ; Kiss, László L. ; Pál, A. ; Kiss, C. ; Sárneczky, Krisztián ; Juhász, Attila ; Hogerheijde, Michiel R. / Evidence for fresh frost layer on the bare nucleus of comet Hale-Bopp at 32 AU distance. In: Astrophysical Journal. 2012 ; Vol. 761, No. 1.
@article{b8a1604a2ca74349988d12d72a72b2da,
title = "Evidence for fresh frost layer on the bare nucleus of comet Hale-Bopp at 32 AU distance",
abstract = "Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already inactive state of the nucleus. The albedo has been found to be surprisingly large (8.1{\%} ± 0.9{\%}), which exceeds the value known for any other comets. With re-reduction of archive Hubble Space Telescope images from 1995 and 1996, we confirm that the pre-perihelion albedo resembled that of an ordinary comet and was smaller by a factor of two than the post-activity albedo. Our further observations with the Very Large Telescope also confirmed that the albedo increased significantly by the end of the activity. We explain these observations by proposing gravitational redeposition of icy grains toward the end of the activity. This is plausible for such a massive body in a cold environment, where gas velocity is lowered to the range of the escape velocity. These observations also show that giant comets are not just the upscaled versions of the comets we know but can be affected by processes that are yet to be fully identified.",
keywords = "comets: general, comets: individual: C/1995 O1 (Hale-Bopp), Oort Cloud",
author = "Szab{\'o}, {Gyula M.} and Kiss, {L{\'a}szl{\'o} L.} and A. P{\'a}l and C. Kiss and Kriszti{\'a}n S{\'a}rneczky and Attila Juh{\'a}sz and Hogerheijde, {Michiel R.}",
year = "2012",
month = "12",
day = "10",
doi = "10.1088/0004-637X/761/1/8",
language = "English",
volume = "761",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Evidence for fresh frost layer on the bare nucleus of comet Hale-Bopp at 32 AU distance

AU - Szabó, Gyula M.

AU - Kiss, László L.

AU - Pál, A.

AU - Kiss, C.

AU - Sárneczky, Krisztián

AU - Juhász, Attila

AU - Hogerheijde, Michiel R.

PY - 2012/12/10

Y1 - 2012/12/10

N2 - Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already inactive state of the nucleus. The albedo has been found to be surprisingly large (8.1% ± 0.9%), which exceeds the value known for any other comets. With re-reduction of archive Hubble Space Telescope images from 1995 and 1996, we confirm that the pre-perihelion albedo resembled that of an ordinary comet and was smaller by a factor of two than the post-activity albedo. Our further observations with the Very Large Telescope also confirmed that the albedo increased significantly by the end of the activity. We explain these observations by proposing gravitational redeposition of icy grains toward the end of the activity. This is plausible for such a massive body in a cold environment, where gas velocity is lowered to the range of the escape velocity. These observations also show that giant comets are not just the upscaled versions of the comets we know but can be affected by processes that are yet to be fully identified.

AB - Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already inactive state of the nucleus. The albedo has been found to be surprisingly large (8.1% ± 0.9%), which exceeds the value known for any other comets. With re-reduction of archive Hubble Space Telescope images from 1995 and 1996, we confirm that the pre-perihelion albedo resembled that of an ordinary comet and was smaller by a factor of two than the post-activity albedo. Our further observations with the Very Large Telescope also confirmed that the albedo increased significantly by the end of the activity. We explain these observations by proposing gravitational redeposition of icy grains toward the end of the activity. This is plausible for such a massive body in a cold environment, where gas velocity is lowered to the range of the escape velocity. These observations also show that giant comets are not just the upscaled versions of the comets we know but can be affected by processes that are yet to be fully identified.

KW - comets: general

KW - comets: individual: C/1995 O1 (Hale-Bopp)

KW - Oort Cloud

UR - http://www.scopus.com/inward/record.url?scp=84870374469&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84870374469&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/761/1/8

DO - 10.1088/0004-637X/761/1/8

M3 - Article

AN - SCOPUS:84870374469

VL - 761

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 8

ER -