Mid-infrared imaging of a circumstellar disk around HR 4796

Mapping the debris of planetary formation

David W Koerner, M. E. Ressler, M. W. Werner, D. E. Backman

Research output: Contribution to journalArticle

132 Citations (Scopus)

Abstract

We report the discovery of a circumstellar disk around the young A0 star HR 4796 in thermal infrared imaging carried out at the W. M. Keck Observatory. By fitting a model of the emission from a fiat dusty disk to an image at λ = 20.8 μm, we derive a disk inclination, i = 72°-9°+6° from face-on, with the long axis of emission at P.A. 28° ± 6°. The intensity of emission does not decrease with radius, as expected for circumstellar disks, but increases outward from the star, peaking near both ends of the elongated structure. We simulate this appearance by varying the inner radius in our model and find an inner hole in the disk with radius Rin = 55 ± 15 AU. This value corresponds to the radial distance of our own Kuiper belt and may suggest a source of dust in the collision of cometesimals. By contrast with the appearance at 20.8 μm, excess emission at λ = 12.5 μm is faint and concentrated at the stellar position. Similar emission is also detected at 20.8 μm in residual subtraction of the best-fit model from the image. The intensity and ratio of flux densities at the two wavelengths could be accounted for by a tenuous dust component that is confined within a few AU of the star with mean temperature of a few hundred degrees K, similar to that of zodiacal dust in our own solar system. The morphology of dust emission from HR 4796 (age 10 Myr) suggests that its disk is in a transitional planet-forming stage, between that of massive gaseous protostellar disks and more tenuous debris disks such as the one detected around Vega.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume503
Issue number1 PART II
StatePublished - 1998
Externally publishedYes

Fingerprint

debris
dust
stars
radii
zodiacal dust
Kuiper belt
solar system
planet
observatory
collision
subtraction
inclination
wavelength
planets
observatories
flux density
collisions
temperature
wavelengths

Keywords

  • Infrared: stars
  • Planetary systems
  • Stars: formation
  • Stars: individual (HR 4796)

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Mid-infrared imaging of a circumstellar disk around HR 4796 : Mapping the debris of planetary formation. / Koerner, David W; Ressler, M. E.; Werner, M. W.; Backman, D. E.

In: Astrophysical Journal, Vol. 503, No. 1 PART II, 1998.

Research output: Contribution to journalArticle

@article{a610be42859b4f9da72ad9aaa5a86119,
title = "Mid-infrared imaging of a circumstellar disk around HR 4796: Mapping the debris of planetary formation",
abstract = "We report the discovery of a circumstellar disk around the young A0 star HR 4796 in thermal infrared imaging carried out at the W. M. Keck Observatory. By fitting a model of the emission from a fiat dusty disk to an image at λ = 20.8 μm, we derive a disk inclination, i = 72°-9°+6° from face-on, with the long axis of emission at P.A. 28° ± 6°. The intensity of emission does not decrease with radius, as expected for circumstellar disks, but increases outward from the star, peaking near both ends of the elongated structure. We simulate this appearance by varying the inner radius in our model and find an inner hole in the disk with radius Rin = 55 ± 15 AU. This value corresponds to the radial distance of our own Kuiper belt and may suggest a source of dust in the collision of cometesimals. By contrast with the appearance at 20.8 μm, excess emission at λ = 12.5 μm is faint and concentrated at the stellar position. Similar emission is also detected at 20.8 μm in residual subtraction of the best-fit model from the image. The intensity and ratio of flux densities at the two wavelengths could be accounted for by a tenuous dust component that is confined within a few AU of the star with mean temperature of a few hundred degrees K, similar to that of zodiacal dust in our own solar system. The morphology of dust emission from HR 4796 (age 10 Myr) suggests that its disk is in a transitional planet-forming stage, between that of massive gaseous protostellar disks and more tenuous debris disks such as the one detected around Vega.",
keywords = "Infrared: stars, Planetary systems, Stars: formation, Stars: individual (HR 4796)",
author = "Koerner, {David W} and Ressler, {M. E.} and Werner, {M. W.} and Backman, {D. E.}",
year = "1998",
language = "English (US)",
volume = "503",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1 PART II",

}

TY - JOUR

T1 - Mid-infrared imaging of a circumstellar disk around HR 4796

T2 - Mapping the debris of planetary formation

AU - Koerner, David W

AU - Ressler, M. E.

AU - Werner, M. W.

AU - Backman, D. E.

PY - 1998

Y1 - 1998

N2 - We report the discovery of a circumstellar disk around the young A0 star HR 4796 in thermal infrared imaging carried out at the W. M. Keck Observatory. By fitting a model of the emission from a fiat dusty disk to an image at λ = 20.8 μm, we derive a disk inclination, i = 72°-9°+6° from face-on, with the long axis of emission at P.A. 28° ± 6°. The intensity of emission does not decrease with radius, as expected for circumstellar disks, but increases outward from the star, peaking near both ends of the elongated structure. We simulate this appearance by varying the inner radius in our model and find an inner hole in the disk with radius Rin = 55 ± 15 AU. This value corresponds to the radial distance of our own Kuiper belt and may suggest a source of dust in the collision of cometesimals. By contrast with the appearance at 20.8 μm, excess emission at λ = 12.5 μm is faint and concentrated at the stellar position. Similar emission is also detected at 20.8 μm in residual subtraction of the best-fit model from the image. The intensity and ratio of flux densities at the two wavelengths could be accounted for by a tenuous dust component that is confined within a few AU of the star with mean temperature of a few hundred degrees K, similar to that of zodiacal dust in our own solar system. The morphology of dust emission from HR 4796 (age 10 Myr) suggests that its disk is in a transitional planet-forming stage, between that of massive gaseous protostellar disks and more tenuous debris disks such as the one detected around Vega.

AB - We report the discovery of a circumstellar disk around the young A0 star HR 4796 in thermal infrared imaging carried out at the W. M. Keck Observatory. By fitting a model of the emission from a fiat dusty disk to an image at λ = 20.8 μm, we derive a disk inclination, i = 72°-9°+6° from face-on, with the long axis of emission at P.A. 28° ± 6°. The intensity of emission does not decrease with radius, as expected for circumstellar disks, but increases outward from the star, peaking near both ends of the elongated structure. We simulate this appearance by varying the inner radius in our model and find an inner hole in the disk with radius Rin = 55 ± 15 AU. This value corresponds to the radial distance of our own Kuiper belt and may suggest a source of dust in the collision of cometesimals. By contrast with the appearance at 20.8 μm, excess emission at λ = 12.5 μm is faint and concentrated at the stellar position. Similar emission is also detected at 20.8 μm in residual subtraction of the best-fit model from the image. The intensity and ratio of flux densities at the two wavelengths could be accounted for by a tenuous dust component that is confined within a few AU of the star with mean temperature of a few hundred degrees K, similar to that of zodiacal dust in our own solar system. The morphology of dust emission from HR 4796 (age 10 Myr) suggests that its disk is in a transitional planet-forming stage, between that of massive gaseous protostellar disks and more tenuous debris disks such as the one detected around Vega.

KW - Infrared: stars

KW - Planetary systems

KW - Stars: formation

KW - Stars: individual (HR 4796)

UR - http://www.scopus.com/inward/record.url?scp=0040826160&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0040826160&partnerID=8YFLogxK

M3 - Article

VL - 503

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 PART II

ER -