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1-1.4 Micron Spectral Atlas of Stars
We present a catalog of J-band (1.08 to 1.35 μm) stellar spectra atlow resolution (R~400). The targets consist of 105 stars ranging inspectral type from O9.5 to M7 and luminosity classes I through V. Therelatively featureless spectra of hot stars, earlier than A4, can beused to remove the atmospheric features which dominate ground-basedJ-band spectroscopy. We measure equivalent widths for three absorptionlines and nine blended features which we identify in the spectra. Usingdetailed comparison with higher resolution spectra, we demonstrate thatlow-resolution data can be used for stellar classification, sinceseveral features depend on the effective temperature and gravity. Forexample, the CN index (1.096-1.104 μm) decreases with temperature,but the strength of a blended feature at 1.28 μm (consisting ofprimarily Pβ) increases. The slope of a star's spectrum can also beused to estimate its effective temperature. The luminosity class of astar correlates with the ratio of the Mg I (1.1831 μm) line to ablend of several species at 1.16 μm. Using these indicators, a starcan be classified to within several subclasses. Fifteen stars withparticularly high and low metal abundances are included in the catalog,and some spectral dependence on metal abundance is also found.
| Proper motion of the star LP 768-500 in Cetus
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Membro dei seguenti gruppi:
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Osservazione e dati astrometrici
| Costellazione: | Balena |
| Ascensione retta: | 01h47m38.20s |
| Declinazione: | -17°13'05.2" |
| Magnitudine apparente: | 8.098 |
| Distanza: | 787.402 parsec |
| Moto proprio RA: | 30.7 |
| Moto proprio Dec: | 2.5 |
| B-T magnitude: | 10.087 |
| V-T magnitude: | 8.263 |
Cataloghi e designazioni:
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