Does ADS 9346 have a low-mass companion?

Abstract Based on the photographic and CCD observations of the relative motion of the A and B components of the binary system ADS 9346 obtained with the 26-inch refractor of Pulkovo Observatory during 1979–2019, we discover an invisible companion associated with star A. Comparison of the ephemerides with the positional and spectroscopic observations allowed us to calculate the preliminary orbit of the photocenter (P = 15 yr). The minimal mass of the companion is approximately 0.13 M ⊙. The existence of the invisible low-mass companion is implied by the IR-excess based on IRAS data. To confirm this, additional observations of the radial velocity near the periastron need to be carried out.

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Period dependent variations of the shell spectrum of V923 AQL

Symposium - International Astronomical Union ◽

10.1017/s0074180900215386 ◽

1994 ◽

Vol 162 ◽

pp. 374-375

Author(s):

Lubomir Iliev

Keyword(s):

Binary System ◽

Radial Velocity ◽

Orbital Period ◽

Be Star ◽

Low Mass ◽

Velocity Variations

V923 Aql is a well known Be star with strong shell spectrum. It was included in the list of shell stars of Merrill and Burwell (1949). A detailed study of the radial velocity variations in the spectrum of the star based on wide collection of spectral observations was presented in the work of Koubsky et al. (1988). In this work an orbital period of 214.756 days was suggested for the binary system consisting of a B5–7 primary and low mass (0.5 Msol).

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The radial velocity variations of WR46 (WN3p)

Symposium - International Astronomical Union ◽

10.1017/s0074180900202040 ◽

1995 ◽

Vol 163 ◽

pp. 245-247

Author(s):

V.S. Niemela ◽

R.H. Barbá ◽

M.M. Shara

Keyword(s):

Binary System ◽

Radial Velocity ◽

Emission Lines ◽

Strong Emission ◽

X Ray ◽

Emission Line Spectrum ◽

Low Mass ◽

Photometric Period ◽

Velocity Variations ◽

X Ray Binaries

Spectral observations of the WN3p star WR46 (HD 104994) obtained during June 1993 and January/February 1994 display large amplitude radial velocity variations of the strong emission lines Nv 4603-19Å and HeII 4686A, on a time scale of a fraction of a day. The most probable period found is 0.311 d, similar to the photometric period found by previous authors. The amplitude of the radial velocity variations of Nv emission is almost twice that of HeII. Noting the similarity of WR46 with low mass X-ray binaries, we suggest that the emission line spectrum corresponds to that of a luminous accretion disk in an evolved binary system.

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Short-Periodic Radial Velocity Variations of the B9P Star ET and

International Astronomical Union Colloquium ◽

10.1017/s0252921100091594 ◽

1986 ◽

Vol 90 ◽

pp. 235-238

Author(s):

E. Gerth

Keyword(s):

Binary System ◽

Radial Velocity ◽

Close Binary System ◽

Close Binary ◽

National Observatory ◽

Spectroscopic Observations ◽

Short Period ◽

Velocity Variations

AbstractSpectroscopic observations of the B9p star ET and secured at the Bulgarian National Observatory Roshen in the years 1981–1984, consisting of 97 plates, show clearly a radial velocity period of 0.198 d - with a ratio to the photometrical period of exactly 2:1. This behaviour would hint at a close binary system; but there arise difficulties in explaining it by this way because of the extreme short period, so that pulsation must be taken into account. However, besides of the confident period of 0.198 d, there is evidence for shorter periods in the region of 45 min, which may be attributed only to pulsational processes.

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A radial velocity study of 4U 2129+47 - A low mass X-ray binary system

The Astrophysical Journal ◽

10.1086/159677 ◽

1982 ◽

Vol 253 ◽

pp. 756 ◽

Cited By ~ 5

Author(s):

J. R. Thorstensen ◽

P. A. Charles

Keyword(s):

Binary System ◽

Radial Velocity ◽

X Ray ◽

Low Mass

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Spectroscopic Observations of Visual Double Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100027536 ◽

1965 ◽

Vol 5 ◽

pp. 109-111

Author(s):

Frederick R. West

Keyword(s):

Radial Velocity ◽

High Dispersion ◽

Velocity Difference ◽

Spectrograph Slit ◽

Spectroscopic Observations ◽

Double Stars ◽

Visual Double Stars ◽

Relative Orbit ◽

Two Component ◽

Star Images

There are certain visual double stars which, when close to a node of their relative orbit, should have enough radial velocity difference (10-20 km/s) that the spectra of the two component stars will appear resolved on high-dispersion spectrograms (5 Å/mm or less) obtainable by use of modern coudé and solar spectrographs on bright stars. Both star images are then recorded simultaneously on the spectrograph slit, so that two stellar components will appear on each spectrogram.

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X-ray and UV emission of the ultrashort-period, low-mass eclipsing binary system BX Trianguli

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834116 ◽

2018 ◽

Vol 619 ◽

pp. A138

Author(s):

V. Perdelwitz ◽

S. Czesla ◽

J. Robrade ◽

T. Pribulla ◽

J. H. M. M. Schmitt

Keyword(s):

Binary System ◽

Light Curve ◽

Binary Systems ◽

Uv Light ◽

Close Binary ◽

Eclipsing Binary ◽

X Ray ◽

Uv Emission ◽

Low Mass ◽

Orbital Modulation

Context.Close binary systems provide an excellent tool for determining stellar parameters such as radii and masses with a high degree of precision. Due to the high rotational velocities, most of these systems exhibit strong signs of magnetic activity, postulated to be the underlying reason for radius inflation in many of the components. Aims.We extend the sample of low-mass binary systems with well-known X-ray properties. Methods.We analyze data from a singular XMM-Newton pointing of the close, low-mass eclipsing binary system BX Tri. The UV light curve was modeled with the eclipsing binary modeling tool PHOEBE and data acquired with the EPIC cameras was analyzed to search for hints of orbital modulation. Results.We find clear evidence of orbital modulation in the UV light curve and show that PHOEBE is fully capable of modeling data within this wavelength range. Comparison to a theoretical flux prediction based on PHOENIX models shows that the majority of UV emission is of photospheric origin. While the X-ray light curve does exhibit strong variations, the signal-to-noise ratio of the observation is insufficient for a clear detection of signs of orbital modulation. There is evidence of a Neupert-like correlation between UV and X-ray data.

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Exoplanet mass estimation for a sample of targets for the Ariel mission

Experimental Astronomy ◽

10.1007/s10686-021-09758-0 ◽

2021 ◽

Author(s):

J. R. Barnes ◽

C. A. Haswell

Keyword(s):

Radial Velocity ◽

Input Parameter ◽

Noise Sources ◽

Time Commitment ◽

Low Mass ◽

Time Required ◽

Fixed Input ◽

The Impact ◽

Quadrature Sampling

AbstractAriel’s ambitious goal to survey a quarter of known exoplanets will transform our knowledge of planetary atmospheres. Masses measured directly with the radial velocity technique are essential for well determined planetary bulk properties. Radial velocity masses will provide important checks of masses derived from atmospheric fits or alternatively can be treated as a fixed input parameter to reduce possible degeneracies in atmospheric retrievals. We quantify the impact of stellar activity on planet mass recovery for the Ariel mission sample using Sun-like spot models scaled for active stars combined with other noise sources. Planets with necessarily well-determined ephemerides will be selected for characterisation with Ariel. With this prior requirement, we simulate the derived planet mass precision as a function of the number of observations for a prospective sample of Ariel targets. We find that quadrature sampling can significantly reduce the time commitment required for follow-up RVs, and is most effective when the planetary RV signature is larger than the RV noise. For a typical radial velocity instrument operating on a 4 m class telescope and achieving 1 m s−1 precision, between ~17% and ~ 37% of the time commitment is spent on the 7% of planets with mass Mp < 10 M⊕. In many low activity cases, the time required is limited by asteroseismic and photon noise. For low mass or faint systems, we can recover masses with the same precision up to ~3 times more quickly with an instrumental precision of ~10 cm s−1.

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BANYAN. III. RADIAL VELOCITY, ROTATION, AND X-RAY EMISSION OF LOW-MASS STAR CANDIDATES IN NEARBY YOUNG KINEMATIC GROUPS

The Astrophysical Journal ◽

10.1088/0004-637x/788/1/81 ◽

2014 ◽

Vol 788 (1) ◽

pp. 81 ◽

Cited By ~ 87

Author(s):

Lison Malo ◽

Étienne Artigau ◽

René Doyon ◽

David Lafrenière ◽

Loïc Albert ◽

...

Keyword(s):

Radial Velocity ◽

Mass Star ◽

X Ray ◽

Low Mass

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Spectrum radial velocity analyser (SERVAL)

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731483 ◽

2017 ◽

Vol 609 ◽

pp. A12 ◽

Cited By ~ 81

Author(s):

M. Zechmeister ◽

A. Reiners ◽

P. J. Amado ◽

M. Azzaro ◽

F. F. Bauer ◽

...

Keyword(s):

Radial Velocity ◽

Line Width ◽

Active Regions ◽

High Signal ◽

Chromatic Index ◽

Visual Channel ◽

Low Mass Stars ◽

Differential Line ◽

Spectral Diagnostics ◽

Low Mass

Context. The CARMENES survey is a high-precision radial velocity (RV) programme that aims to detect Earth-like planets orbiting low-mass stars. Aims. We develop least-squares fitting algorithms to derive the RVs and additional spectral diagnostics implemented in the SpEctrum Radial Velocity AnaLyser (SERVAL), a publicly available python code. Methods. We measured the RVs using high signal-to-noise templates created by coadding all available spectra of each star. We define the chromatic index as the RV gradient as a function of wavelength with the RVs measured in the echelle orders. Additionally, we computed the differential line width by correlating the fit residuals with the second derivative of the template to track variations in the stellar line width. Results. Using HARPS data, our SERVAL code achieves a RV precision at the level of 1 m/s. Applying the chromatic index to CARMENES data of the active star YZ CMi, we identify apparent RV variations induced by stellar activity. The differential line width is found to be an alternative indicator to the commonly used full width half maximum. Conclusions. We find that at the red optical wavelengths (700–900 nm) obtained by the visual channel of CARMENES, the chromatic index is an excellent tool to investigate stellar active regions and to identify and perhaps even correct for activity-induced RV variations.

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