2002A&A...388..298F


C.D.S. - SIMBAD4 rel 1.7 - 2019.09.22CEST11:20:29

2002A&A...388..298F - Astronomy and Astrophysics, volume 388, 298-308 (2002/6-2)

Hα spectroscopy and BV photometry of RT Lacertae.

FRASCA A., CAKIRLI O., CATALANO S., IBANOGLU C., MARILLI E., EVREN S. and TAS G.

Abstract (from CDS):

Contemporaneous spectroscopic and photometric B V observations of the RS CVn type eclipsing binary RT Lacertae were performed in summer 2000. The photometric observations were obtained at the Ege University Observatory, while the spectroscopic ones were carried out at Catania Astrophysical Observatory in the spectral range 5860-6700Å. We obtained a high quality radial velocity curve of the system that allowed us to give more accurate values of the orbital parameters. A steady decrease of the barycentric velocity from 1920 to 2000 has been pointed out and has been discussed in the context of a third body hypothesis. Through the subtraction of a ``synthetic'' spectrum, built up with spectra of inactive standard stars, we detected Hα excess emission which fills in the photospheric absorption profiles of both components. With the exception of a few spectra, taken close to the eclipses, in which some extra absorption or a faint double-peaked broad emission appears, there is no further evidence of circumstellar matter in this system, as suggested in previous works. The hotter and more massive star appears also as the more active at a chromospheric level, since it has a Hα flux about ten times greater than the companion, on average. Rotational modulation of the Hα emission has been detected in both stars. The hemisphere of the more massive star facing the observer at phase 0.75p appears brighter (in Hα) than that seen at phase 0.25p, while for the less massive G9 IV star the maximum Hα emission is seen around phase 0.0p-0.1p. From the analysis of the contemporaneous light curve (Lanza et al., 2002A&A...386..583L), the more massive G5 IV star results to be more active than the companion at a photospheric level, in agreement with the chromospheric behaviour observed in Hα. In addition, the starspots of the G5 IV star are mainly located in the Hα brighter hemisphere, suggesting a close spatial association of spots and plages in this star. The G9 IV star displays instead the maximum Hα emission at the phase of maximum visibility of the smaller spotted area found from the light-curve analysis. The minimum Hα emission occurs when the more heavily spotted region is visible.

Abstract Copyright:

Journal keyword(s): stars: activity - stars: binaries: spectroscopic - stars: late-type - stars: starspots - stars: individual: RT Lac

VizieR on-line data: <Available at CDS (J/A+A/388/298): table1.dat>

Simbad objects: 15

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Number of rows : 15

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 HD 8357 XB* 01 22 56.7569725665 +07 25 09.324761789 8.530 8.160   6.8   G5 154 0
2 V* XX Tri RS* 02 03 47.1138016857 +35 35 28.669244792   9.52 8.42     K0III 116 0
3 V* UX Ari RS* 03 26 35.3764089427 +28 42 54.211100955 7.76 7.28 6.37     K0IV 655 0
4 HD 22468 RS* 03 36 47.2911034958 +00 35 15.938962144 7.09 6.63   5.4   K2:Vnk 1115 0
5 V* TX UMa Al* 10 45 20.5033114027 +45 33 58.703967287   6.99 6.98     B8V+G0III-IV 270 0
6 V* U CrB Al* 15 18 11.3525714546 +31 38 49.412035589   7.79 7.83     B6V 246 0
7 * mu. Her ** 17 46 27.5266778 +27 43 14.437984 4.56 4.17 3.42 2.89 2.51 G5IV 635 1
8 HD 174237 Be* 18 46 43.0889592280 +52 59 16.650319177 5.06 5.80 5.90     B3+F5III 186 0
9 * b Aql PM* 19 24 58.2002406780 +11 56 39.882312617 6.35 5.93   4.7   G7IVHdel1 444 0
10 V* V1817 Cyg RS* 19 31 13.5555646958 +55 43 54.606371185   7.489 6.369     K2II-III+A0V 141 0
11 * eps Cyg ** 20 46 12.6823609 +33 58 12.924926 4.370 3.520 2.480 1.73 1.19 K0III 475 1
12 HD 209219 * 22 00 36.5275151830 +44 06 18.530689222   8.73 7.38     K2 14 0
13 HD 209220 PM* 22 00 40.5172535154 +44 02 12.386279468   8.88 8.53     F8 9 0
14 V* RT Lac RS* 22 01 30.7407751260 +43 53 25.640188873   10.092 8.84     G9+K1IVIV 261 0
15 HD 224085 RS* 23 55 04.0516465022 +28 38 01.248194500 8.88 8.20   6.9   K2+IVeFe-1 672 0

    Equat.    Gal    SGal    Ecl

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2019.09.22-11:20:29

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