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HD 199090


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관련 글

2MASS J20261584–2943124: an Unresolved L0.5 + T6 Spectral Binary
We identify the L dwarf 2MASS J20261584–2943124 as an unresolvedspectral binary, based on low-resolution, near-infrared spectroscopyfrom IRTF/SpeX. The data reveal a peculiar absorption feature at 1.6?m, previously noted in the spectra of other very low-mass spectralbinaries, which likely arises from overlapping FeH and CH4absorption bands in the blended light of an L dwarf/T dwarf pair.Spectral template matching analysis indicates component types of L0.5and T6, with relative brightness ?H = 4.2 ± 0.6. Laserguide star adaptive optics imaging observations with Keck/NIRC2 fail toresolve the source, indicating a maximum separation at the observingepoch of 0farcs25, or a projected separation of 9 AU assuming a distanceof 36 ± 5 pc. With an age that is likely to be relatively older(gsim5 Gyr) based on the system's large V tan and mass ratioarguments, the relative motion of the potentially "massive" (0.06-0.08 Msun) components of 2MASS J2026–2943 may be detectablethrough radial velocity variations, like its earlier-type counterpart2MASS J03202839–0446358 (M8+T5), providing dynamical massmeasurements that span the hydrogen burning limit.Some of the data presented herein were obtained at the W. M. KeckObservatory, which is operated as a scientific partnership among theCalifornia Institute of Technology, the University of California, andthe National Aeronautics and Space Administration. The Observatory wasmade possible by the generous financial support of the W. M. KeckFoundation.

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관측 및 측정 데이터

별자리:현미경자리
적경:20h55m54.46s
적위:-31°30'20.4"
가시등급:7.91
거리:179.856 파섹
적경상의 고유운동:37.2
적위상의 고유운동:-6.4
B-T magnitude:8
V-T magnitude:7.918

천체목록:
일반명   (Edit)
HD 1989HD 199090
TYCHO-2 2000TYC 7458-420-1
USNO-A2.0USNO-A2 0525-42923466
HIPHIP 103315

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