<i>UBV</i> photometry of Be stars at Hvar: 1972–1990

Pavlovski, K.; Harmanec, P.; Božić, H.; Koubský, P.; Hadrava, Petr; Kriz, S.; Ruzic, Z.; Štefl, S.

doi:10.1051/aas:1997213

Cited by 58 publications

(55 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using Hipparcos photometry Hubert &: Floquet (1998) have extended the outburst detection to a very large number of Be stars, some of them having been poorly observed in photometry and/or in spectroscopy up to now; outbursts have been preferentially detected with a higher level (AHp < 0.3 mag) in early Be stars with a low to moderate vsini. Pavlovski et al (1998) derived the same conclusion from their investigation of Hvar survey data (Pavlovski et al 1997). …”

Section: Introductionmentioning

confidence: 63%

Short-lived and Long-lived Outbursts in B and Be Stars from Hipparcos Photometry and Modelling

Hubert¹,

Floquet²,

Zorec

2000

International Astronomical Union Colloquium

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 63%

Short-lived and Long-lived Outbursts in B and Be Stars from Hipparcos Photometry and Modelling

Hubert¹,

Floquet²,

Zorec

2000

International Astronomical Union Colloquium

View full text Add to dashboard Cite

show abstract

“…Re-analysis of the publicly available photometric data (Guo et al 1995;Pavlovski et al 1997;Harmanec et al 1997, and data from the HIPPARCOS-mission) did not confirm the presence of photometric eclipses suggested by Božić & Pavlovski (1988). Rather, the fainting at phase zero they observed seems to be an event unrelated to the orbital phase.…”

Section: Binaritymentioning

confidence: 91%

Cyclic variability of the circumstellar disk of the Be starζ Tauri

Štefl¹,

Rivinius²,

Carciofi

et al. 2009

A&A

Self Cite

View full text Add to dashboard Cite

Context. Emission lines formed in decretion disks of Be stars often undergo long-term cyclic variations, especially in the violet-to-red (V/R) ratio of their primary components. The underlying structural and dynamical variations of the disks are only partly understood. From observations of the bright Be-shell star ζ Tau, the possibly broadest and longest data set illustrating the prototype of this behaviour was compiled from our own and archival observations. It comprises optical and infrared spectra, broad-band polarimetry, and interferometric observations. Aims. The dense, long-time monitoring permits a better separation of repetitive and ephemeral variations. The broad wavelength coverage includes lines formed under different physical conditions, i.e. different locations in the disk, so that the dynamics can be probed throughout much of the disk. Polarimetry and interferometry constrain the spatial structure. All together, the objective is a better understand the dynamics and life cycle of decretion disks. Methods. Standard methods of data acquisition, reduction, and analysis were applied. Results. From 3 V/R cycles between 1997 and 2008, a mean cycle length in Hα of 1400-1430 days was derived. After each minimum in V/R, the shell absorption weakens and splits into two components, leading to 3 emission peaks. This phase may make the strongest contribution to the variability in cycle length. There is no obvious connection between the V/R cycle and the 133-day orbital period of the not otherwise detected companion. V/R curves of different lines are shifted in phase. Lines formed on average closer to the central star are ahead of the others. The shell absorption lines fall into 2 categories differing in line width, ionization/excitation potential, and variability of the equivalent width. They seem to form in separate regions of the disk, probably crossing the line of sight at different times. The interferometry has resolved the continuum and the line emission in Brγ and HeI 2.06. The phasing of the Brγ emission shows that the photocenter of the line-emitting region lies within the plane of the disk but is offset from the continuum source. The plane of the disk is constant throughout the observed V/R cycles. The observations lay the foundation for the fully self-consistent, one-armed, disk-oscillation model developed in Paper II.

show abstract

“…Very useful and revealing survey work has been presented by Hubert & Floquet (1998), Moujtahid et al (1998), and Pavlovski et al (1997).…”

Section: Disk Growthmentioning

confidence: 99%

“…The outburst model: Hipparcos and Hvar photometric surveys (Hubert & Floquet 1998, Pavlovski et al 1997) have led to interesting results regarding photospheric outbursts in Be stars. Although these surveys cannot distinguish between magnetic or pulsational origin of the outbursts, they both conclude that short term variations in the form of outbursts are a lot more abundant in earlytype than in late-type Be stars.…”

Section: Applicable)mentioning

confidence: 99%

Long-term Variability in Be-Star disks

Telting

2000

International Astronomical Union Colloquium

View full text Add to dashboard Cite

Abstract.Be stars can switch between non-disk, gradual disk growth, disk-loss events, and shell-line phases. Many aspects of this Be phenomenon are still not understood. In this paper I review recent work on variability in Be-star disks, divided in four different topics: disk growth (Section 1), long-term V/R variations and global disk oscillations (Section 2), spectacular variations (Section 3), and, concisely, the disk variability in Be/X-ray binaries (Section 4).

show abstract

UBV photometry of Be stars at Hvar: 1972–1990

Cited by 58 publications

References 47 publications

Short-lived and Long-lived Outbursts in B and Be Stars from Hipparcos Photometry and Modelling

Short-lived and Long-lived Outbursts in B and Be Stars from Hipparcos Photometry and Modelling

Cyclic variability of the circumstellar disk of the Be starζ Tauri

Long-term Variability in Be-Star disks

Contact Info

Product

Resources

About