2001A&A...375..100M


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.28CET21:29:53

2001A&A...375..100M - Astronomy and Astrophysics, volume 375, 100-112 (2001/8-3)

New physical elements of HR 7428 and its Hα behaviour.

MARINO G., CATALANO S., FRASCA A. and MARILLI E.

Abstract (from CDS):

object{HR 7428} is a spectroscopic binary composed of a K2 II-III and a main-sequence A2 star. Thanks to a new set of radial velocity measurements from our and IUE spectroscopy we have improved the orbital period determination and the spectroscopic elements of both components. Combining optical photometry and UV low dispersion IUE spectra we have determined new stellar parameters through photospheric synthetic spectra using the NextGen models by Hauschildt et al. (1999ApJ...512..377H, 1999ApJ...525..871H). The hot secondary component parameters agree with those of a typical A2 V star while the radius of the primary cool star turns out to be 40R, i.e. significantly smaller than a previous estimate of 62R. The position of the hot and cool component on the H-R diagram is consistent with a normal evolution, without any mass exchange, of this binary system, whose age is in the range 100-200Myrs. The system displays a filled-in Hα profile with significant variations both in depth and width along the orbital phase. In addition to the Hα chromospheric emission component, we have detected, at some phases, a broad extra-absorption and emission that we relate to an inter-system cloud.

Abstract Copyright:

Journal keyword(s): stars: activity - stars: binaries: spectroscopic - stars: individual: HR 7428

Simbad objects: 9

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Number of rows : 9

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 * alf Ari PM* 02 07 10.40570 +23 27 44.7032 4.29 3.17 2.01 1.15 0.54 K2-IIIbCa-1 607 1
2 V* SU Aur Or* 04 55 59.3861369488 +30 34 01.499800471   10.33 9.30 9.17   G2IIIne 538 0
3 * eps Aur Al* 05 01 58.1290610816 +43 49 23.871349520 3.86 3.53 2.99 2.47 2.02 A9Ia 558 0
4 * alf Boo RG* 14 15 39.67207 +19 10 56.6730 2.46 1.18 -0.05 -1.03 -1.68 K1.5IIIFe-0.5 2148 0
5 V* SS Boo RS* 15 13 32.5313815658 +38 34 05.557651289   10.95 10.19     G8V 131 0
6 * bet Oph PM* 17 43 28.3526482 +04 34 02.295484 5.150 3.930 2.750 1.96 1.38 K2IIICN0.5 455 0
7 * alf Lyr dS* 18 36 56.33635 +38 47 01.2802 0.03 0.03 0.03 0.07 0.10 A0Va 2521 0
8 V* V1817 Cyg RS* 19 31 13.5555646958 +55 43 54.606371185   7.489 6.369     K2II-III+A0V 143 0
9 V* AR Lac RS* 22 08 40.8180372773 +45 44 32.104045703 7.09 6.83 6.11     K0IVe+G5IV 697 0

    Equat.    Gal    SGal    Ecl

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2020.10.28-21:29:53

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