Photographic observations of visual double 
stars

Jasinta, D. M. D.; Raharto, Moedji; Soegiartini, Endang

doi:10.1051/aas:1999121

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Jasinta, Raharto, and Soegiartini (1995) also report this object with separation of 4.96 ′′ at PA 37.8 • , and identical brightness relative to the primary star. Given HD 211415's large proper motion of 771 mas/yr at PA 124.8 •(Perryman et al 1997), this must be a bound companion star in a nearly edge-on orbit with semi-major axis ∼ 100 AU.…”

mentioning

confidence: 56%

HST and Spitzer Observations of the HD 207129 Debris Ring

Krist,

Stapelfeldt,

Bryden

et al. 2010

Preprint

View full text Add to dashboard Cite

A debris ring around the star HD 207129 (G0V; d = 16.0 pc) has been imaged in scattered visible light with the ACS coronagraph on the Hubble Space Telescope and in thermal emission using MIPS on the Spitzer Space Telescope at λ = 70 µm (resolved) and 160 µm (unresolved). Spitzer IRS (λ = 7-35 µm) and MIPS (λ = 55-90 µm) spectrographs measured disk emission at λ > 28 µm. In the HST image the disk appears as a ∼30 AU wide ring with a mean radius of ∼163 AU and is inclined by 60 • from pole-on. At 70 µm it appears partially resolved and is elongated in the same direction and with nearly the same size as seen with HST in scattered light. At 0.6 µm the ring shows no significant brightness asymmetry, implying little or no forward scattering by its constituent dust. With a mean surface brightness of V = 23.7 mag arcsec −2 , it is the faintest disk imaged to date in scattered light.We model the ring's infrared spectral energy distribution using a dust population fixed at the location where HST detects the scattered light. The observed SED is well-fit by this model, with no requirement for additional unseen debris zones. The firm constraint on the dust radial distance breaks the usual grain size-distance degeneracy that exists in modeling of spatially unresolved disks, and allows us to infer a minimum grain size of ∼ 2.8µm and a dust size distribution power law spectral index of -3.9. An

show abstract

mentioning

confidence: 56%

HST and Spitzer Observations of the HD 207129 Debris Ring

Krist,

Stapelfeldt,

Bryden

et al. 2010

Preprint

View full text Add to dashboard Cite

show abstract

“…This may be due to the binary companion truncating the outer edge of a circumstellar disk around one of the stars. The binary pair is separated by 2.4 arcseconds (or 182 AU projected on the sky) and is a resolved pair of equal magnitude stars of likely the same mass (Jasinta, Raharto & Soegiartini 1999). If the emission were the result of a bow wave, the ISM cloud could encompass both stars (e.g.…”

Section: Starmentioning

confidence: 99%

IR excesses around nearby Lambda Boo stars are caused by debris discs rather than ISM bow waves

Draper¹,

Matthews²,

Kennedy³

et al. 2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

Lambda Boo stars are predominately A-type stars with solar abundant C, N, O, and S, but up to 2 dex underabundances of refractory elements. The stars' unusual surface abundances could be due to a selective accretion of volatile gas over dust. It has been proposed that there is a correlation between the Lambda Boo phenomenon and IR-excesses which are the result of a debris disk or interstellar medium (ISM) interaction providing the accreting material. We observe 70 or 100 and 160 µm excess emission around 9 confirmed Lambda Boo stars with the Herschel Space Observatory, to differentiate whether the dust emission is from a debris disk or an ISM bow wave. We find that 3/9 stars observed host well resolved debris disks. While the remaining 6/9 are not resolved, they are inconsistent with an ISM bow wave based on the dust emission being more compact for its temperature and predicted bow wave models produce hotter emission than what is observed. We find the incidence of bright IRexcesses around Lambda Boo stars is higher than normal A-stars. To explain this given our observations, we explore Poynting-Robertson (PR) drag as a mechanism of accretion from a debris disk but find it insufficient. As an alternative, we propose the correlation is due to higher dynamical activity in the disks currently underway. Large impacts of planetesimals or a higher influx of comets could provide enough volatile gas for accretion. Further study on the transport of circumstellar material in relation to the abundance anomalies are required to explain the phenomenon through external accretion.

show abstract

“…About 9000 plates of astrometric images of visual double stars with angular separations in the range of 2"-20" have been obtained through the visual telescope. The recent published data for visual double stars can be found in Jasinta et al (1994, Jasinta and Hidayat (1999).…”

Section: Contribution To Astronomymentioning

confidence: 99%