The pre-main-sequence star V1184 Tauri (CB 34V) at the end of prolonged eclipse

Abstract

Aims. V1184 Tau (CB 34V) lies in the field of the Bok globule CB 34 and was discovered as a large amplitude variable in 1993. According to the first hypothesis of the variability of the star, it is a FU Orionis candidate erupted between 1951 and 1993. During subsequent observations, the star manifests large amplitude variability interpreted as obscuration from circumstellar clouds of dust. We included V1184 Tau (CB 34V) in our target list of highly variable pre-main-sequence stars to determine the reasons for the variations in the brightness of this object. Methods. Data from BVRI photometric observations of the young stellar object V1184 Tau, obtained in the period 2008−2015, are presented in the paper. These data are a continuation of our optical photometric monitoring of the star began in 2000 and continuing to date. The photometric observations of V1184 Tau were performed in two observatories with two medium-sized and two small telescopes. Results. Our results indicate that during periods of maximum light the star shows characteristics typical of T Tauri stars. During the observed deep minimum in brightness, however, V1184 Tau is rather similar to UX Orionis objects. The deep drop in brightness began in 2003 ended in 2015 as the star has returned to maximum light. The light curve during the drop is obviously asymmetric as the decrease in brightness lasts two times longer than the rise. The observed colour reverse on the colour-magnitude diagrams is also confirmation of obscuration from circumstellar clouds of dust as a reason for the large amplitude variability in the brightness.

V2492 Cygni: Optical BVRI Variability During the Period 2010–2017

“…Both types of variability can act independently during different time periods and the result is the complicated light curve of V2492 Cyg. A similar superposition of the both types of variability (accretion and obscuration) is seen on the long-term light curve of other PMS stars − V582 Aurigae (Semkov et al 2013), V1647 Orionis (Aspin et al 2009), GM Cephei (Semkov et al 2015a), and V1184 Tauri (Barsunova et al 2006, Semkov et al 2015b).…”

A new insight into the variability of V1184 Tauri

“…Optical photometry in BVRI that was obtained between 2002 and 2007 have been reported by Yun et al 1997, Semkov 2003, 2004a, 2004b, 2006, Semkov et al 2008, and by Grinin et al 2009. Photometry in the period 2008−2015 (mainly in V and I bands) is available from the American Association of Variable Star Observers (AAVSO) webpage (www.aavso.org/) and recently published by Semkov et al (2015). Further photometric points were obtained by us together with the optical spectra (see Sect.…”

“…Their original classification of V1184 Tau as a FUor system has been reconsidered in the light of more recent observational studies. Its recent history has been monitored by Semkov (2004aSemkov ( , 2004bSemkov ( , 2006 and by Semkov et al (2008Semkov et al ( , 2015 who rejected the FUor original hy-pothesis and classified V1184 Tau as an UXor object that exhibits extinction-driven variations. Indeed, until 2004, the star presented quite a constant flux level (I ∼ 13.0 mag), followed by a slow but deep fading (from 2004 to 2006, called the '2004 photometric catastrophe') down to I ∼ 17 mag, overlapped by short-time variability episodes (with amplitude of up to 0.6-0.8 mag in the J band), which occur on timescales of days.…”

EXors and the stellar birthline

“…For example, the embedded source decay time was a decade (Kóspál et al 2006), in violation of our basic selection criterion. The star GM Cep has displayed rapid, low-amplitude (1−2 mag) oscillations in luminosity, not temporally isolated outbursts (Sicilia-Aguilar et al 2008;Semkov et al 2015). 2 We thank Dario Lorenzetti for providing R-values for all the sources in Table 1. A133, page 2 of 6 References.…”