TY - JOUR
T1 - Discovery of an 86 AU radius debris ring around HP 181327
AU - Schneider, Glenn
AU - Silverstone, Murray D.
AU - Hines, Dean C.
AU - Augereau, Jean Charles
AU - Pinte, Christophe
AU - Ménard, François
AU - Krist, John
AU - Clampin, Mark
AU - Grady, Carol
AU - Golimowski, David
AU - Ardila, David
AU - Henning, Thomas
AU - Wolf, Sebastian
AU - Rodmann, Jens
PY - 2006/10/10
Y1 - 2006/10/10
N2 - HST NICMOS PSF-subtracted coronagraphic observations of HD 181327 have revealed the presence of a ringlike disk of circumstellar debris seen in 1.1 μm light scattered by the disk grains, surrounded by a diffuse outer region of lower surface brightness. The annular disk appears to be inclined by 31.°7 ± 1.°6 from face-on, with the disk major-axis P.A. at 107° ± 2°. The total 1.1 μm flux density of the light scattered by the disk (at 1.″2 < r < 5.″0) of 9.6 ± 0.8 mJy is 0.17% ± 0.015% of the starlight. Seventy percent of the light from the scattering grains appears to be confined in a 36 AU wide annulus centered on the peak of the radial surface brightness (SB) profile 86.3 ± 3.9 AU from the star, well beyond the characteristic radius of thermal emission estimated from IRAS and Spitzer flux densities, assuming black-body grains (≈22 AU). The 1.1 μm light scattered by the ring (1) appears bilaterally symmetric, (2) exhibits directionally preferential scattering well represented by a Henyey-Greenstein scattering phase function with gHG = 0.30 ± 0.03, and (3) has a median SB (over all azimuth angles) at the 86.3 AU radius of peak SB of 1.00 ± 0.07 mJy arcsec-2. No photocentric offset is seen in the ring relative to the position of the central star. A low SB diffuse halo is seen in the NICMOS image to a distance of ∼4″. Deeper 0.6 μm Hubble Space Telescope (HST) ACS PSF-subtracted coronagraphic observations reveal a faint (V ≈ 21.5 mag arcsec-2) outer nebulosity at 4″ < r < 9″, asymmetrically brighter to the north of the star. We discuss models of the disk and properties of its grains, from which we infer a maximum vertical scale height of 4-8 AU at the 87.6 AU radius of maximum surface density, and a total maximum dust mass of collisionally replenished grains with minimum grain sizes of ≈1 μm of ≈4MMoon.
AB - HST NICMOS PSF-subtracted coronagraphic observations of HD 181327 have revealed the presence of a ringlike disk of circumstellar debris seen in 1.1 μm light scattered by the disk grains, surrounded by a diffuse outer region of lower surface brightness. The annular disk appears to be inclined by 31.°7 ± 1.°6 from face-on, with the disk major-axis P.A. at 107° ± 2°. The total 1.1 μm flux density of the light scattered by the disk (at 1.″2 < r < 5.″0) of 9.6 ± 0.8 mJy is 0.17% ± 0.015% of the starlight. Seventy percent of the light from the scattering grains appears to be confined in a 36 AU wide annulus centered on the peak of the radial surface brightness (SB) profile 86.3 ± 3.9 AU from the star, well beyond the characteristic radius of thermal emission estimated from IRAS and Spitzer flux densities, assuming black-body grains (≈22 AU). The 1.1 μm light scattered by the ring (1) appears bilaterally symmetric, (2) exhibits directionally preferential scattering well represented by a Henyey-Greenstein scattering phase function with gHG = 0.30 ± 0.03, and (3) has a median SB (over all azimuth angles) at the 86.3 AU radius of peak SB of 1.00 ± 0.07 mJy arcsec-2. No photocentric offset is seen in the ring relative to the position of the central star. A low SB diffuse halo is seen in the NICMOS image to a distance of ∼4″. Deeper 0.6 μm Hubble Space Telescope (HST) ACS PSF-subtracted coronagraphic observations reveal a faint (V ≈ 21.5 mag arcsec-2) outer nebulosity at 4″ < r < 9″, asymmetrically brighter to the north of the star. We discuss models of the disk and properties of its grains, from which we infer a maximum vertical scale height of 4-8 AU at the 87.6 AU radius of maximum surface density, and a total maximum dust mass of collisionally replenished grains with minimum grain sizes of ≈1 μm of ≈4MMoon.
KW - Circumstellar matter
KW - Infrared: stars
KW - Planetary systems: protoplanetary disks
KW - Stars: individual (HD 181327)
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U2 - 10.1086/506507
DO - 10.1086/506507
M3 - Article
AN - SCOPUS:33846861477
SN - 0004-637X
VL - 650
SP - 414
EP - 431
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 I
ER -