The 1960 Minimum of R Coronae Borealis.

Payne-Gaposchkin, Cecilia

doi:10.1086/147647

Cited by 51 publications

(45 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some of the differences between classical R CrB stars and the fainter DY Per class remarked upon within the LMC were noted by Payne-Gaposchkin (1963) and others in between. This somehow implies that there must also be such stars in the Milky Way.…”

Section: Is This the English-speaking Tour?mentioning

confidence: 85%

Astrophysics in 2002

Trimble

Aschwanden

2003

PUBL ASTRON SOC PAC

View full text Add to dashboard Cite

ABSTRACT. This has been the Year of the Baryon. Some low temperature ones were seen at high redshift, some high temperature ones were seen at low redshift, and some cooling ones were (probably) reheated. Astronomers saw the back of the Sun (which is also made of baryons), a possible solution to the problem of ejection of material by Type II supernovae (in which neutrinos push out baryons), the production of R Coronae Borealis stars (previously-owned baryons), and perhaps found the missing satellite galaxies (whose failing is that they have no baryons). A few questions were left unanswered for next year, and an attempt is made to discuss these as well.

show abstract

Section: Is This the English-speaking Tour?mentioning

confidence: 85%

Astrophysics in 2002

Trimble

Aschwanden

2003

PUBL ASTRON SOC PAC

View full text Add to dashboard Cite

show abstract

“…in early 1986 at two observatories, in the Crimea (1.2 m telescope + photometer/polarimeter of Helsinki University- Piirola, 1975) and on the Sanglok (Tajikistan) 1 m telescope. A part of the observations of UX Ori were made in 1986 at the Soviet-Bolivian Observatory.…”

Section: A) H O W It Was Made?mentioning

confidence: 99%

Young stars with non-periodic algol-type minima

Гринин

1992

Astronomical & Astrophysical Transactions

View full text Add to dashboard Cite

The irregular variability is one of the most important properties of young stellar objects and is of great interest since its understanding is the key to understanding the physics of young stars. The main question is: how to separate, in each concrete case, the different potentially important mechanisms of the variability, such as the variable circumstellar extinction, the flare (and chromospheric) activity, and the suppression of stellar photosphere by the formation of magnetic spots? We consider this question below in application to an interesting subclass of young stars, the stars with non-periodic Algol-type minima. The most important results of current investigations of these stars are discussed.

show abstract

“…The dust clouds are then driven away from the star by radiation pressure. An alternative model proposes that the dust is formed close to the star and moves quickly away due to radiation pressure (originally proposed by Payne-Gaposchkin 1963). However, the conditions close to the star are far from the thermodynamic equilibrium necessary to form dust grains, though as discussed by Clayton (1996) and Donn (1967), the condensation temperature of carbon in a hydrogen deficient environment, such as on an R CrB star, is much higher than when hydrogen is present.…”

Section: Introductionmentioning

confidence: 99%

Direct imaging of a massive dust cloud around R Coronae Borealis

Jeffers¹,

Min²,

Waters³

et al. 2012

A&A

View full text Add to dashboard Cite

We present recent polarimetric images of the highly variable star R CrB using ExPo and archival WFPC2 images from the HST. We observed R CrB during its current dramatic minimum where it decreased more than 9 mag due to the formation of an obscuring dust cloud. Since the dust cloud is only in the line-of-sight, it mimics a coronograph allowing the imaging of the star's circumstellar environment. Our polarimetric observations surprisingly show another scattering dust cloud at approximately 1.3 or 2000 AU from the star. We find that to obtain a decrease in the stellar light of 9 mag and with 30% of the light being reemitted at infrared wavelengths (from R CrB's SED) the grains in R CrB's circumstellar environment must have a very low albedo of approximately 0.07%. We show that the properties of the dust clouds formed around R CrB are best fitted using a combination of two distinct populations of grains size. The first are the extremely small 5 nm grains, formed in the low density continuous wind, and the second population of large grains (∼0.14 μm) which are found in the ejected dust clouds. The observed scattering cloud, not only contains such large grains, but is exceptionally massive compared to the average cloud.

show abstract

The 1960 Minimum of R Coronae Borealis.

Cited by 51 publications

References 0 publications

Astrophysics in 2002

Astrophysics in 2002

Young stars with non-periodic algol-type minima

Direct imaging of a massive dust cloud around R Coronae Borealis

Contact Info

Product

Resources

About