Home     Per cominciare     Sopravvivere Nell'Universo    
Inhabited Sky
    News@Sky     Astro Foto     La collezione     Forum     Blog New!     FAQ     Stampa     Login  

TYC 2240-482-1


Contenuti

Immagini

Carica la tua immagine

DSS Images   Other Images


Articoli relazionati

Doppler imaging of stellar surface structure. XV. A possible detection of differential rotation and local meridional flows on the rapidly-rotating giant HD 218153 = KU Pegasi
Time-resolved Doppler images of the rapidly rotating, but long-period(25 days), giant KU Pegasi show several cool low-to-medium latitudespots as well as an asymmetric polar feature. The average spottemperature is about 700 K below the photospheric temperature of 4700 K.KU Peg is one of the most massive, and currently the most evolved,late-type star with a Doppler image. We obtained two independent imagesfrom two consecutive stellar rotations covering 50 nights with a totalof 43 spectra. From a cross-correlation analysis of the two maps, wedetect systematic longitudinal and latitudinal shifts that wetentatively interpret as latitude-dependent differential rotation andlocal meridional flows, respectively. The differential-rotation patternis more complex than on the Sun, but on average in the sense that thepoles rotate slower than the stellar equator, i.e. in the same directionand also of the same order than on the Sun. The latitudinal shifts areof the order of 0.4° day-1 towards the stellar pole andoccur at longitudes of around 40° and 330°. The residual{Hα } profiles show a stationary emission component at restwavelength and a blue-shifted absorption. The latter suggests an outwardpointed velocity field with a flow velocity of approximately 35 kms-1.

Starspot photometry with robotic telescopes. UBV(RI)_C and by light curves of 47 active stars in 1996/97
We present continuous multicolor photometry for 47 stars from October1996 through June 1997. Altogether, 7073 V(RI)_c, UBV, and by datapoints, each the average of three individual readings, were acquiredwith three automatic photoelectric telescopes (APTs) at FairbornObservatory in southern Arizona. Most of our targets arechromospherically active single and binary stars of spectral type G to Kbut there are also four pre-main-sequence objects and three pulsatingstars in our sample. The light variability is generally due torotational modulation of an asymmetrically spotted stellar surface andtherefore precise rotational periods and their seasonal variations aredetermined from Fourier analysis. We also report on photometricvariations of gamma CrB (A0V) with a period of 0.44534 days. All dataare available in numerical form. All data are available from CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html

Sottometti un nuovo articolo


Link relazionati

  • - Nessun link trovato -
Sottometti un nuovo link


Membro dei seguenti gruppi:


Osservazione e dati astrometrici

Costellazione:Pegaso
Ascensione retta:23h11m05.18s
Declinazione:+25°22'01.0"
Magnitudine apparente:8.236
Distanza:515.464 parsec
Moto proprio RA:-3.8
Moto proprio Dec:-25
B-T magnitude:10.068
V-T magnitude:8.388

Cataloghi e designazioni:
Nomi esatti   (Edit)
TYCHO-2 2000TYC 2240-482-1
USNO-A2.0USNO-A2 1125-19699791
HIPHIP 114479

→ Richiesta di ulteriori cataloghi da VizieR