scholarly journals HS 2237+8154: A New Pre-CV just above the Period Gap

2004 ◽  
Vol 194 ◽  
pp. 271-271
Author(s):  
B. T. Gänsicke ◽  
S. Araujo-Betancor ◽  
H.-J. Hagen ◽  
E. T. Harlaftis ◽  
S. Kitsionas ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Orbital Period ◽  
Velocity Variation ◽  
Cataclysmic Variable ◽  
Evolutionary State ◽  
Radial Velocity Variation

We report follow-up observations of the new pre-cataclysmic variable HS 2237+8154, identified from the Hamburg Quasar Survey. The orbital period derived from ellipsoidal modulation observed in the iR-band as well as from the Hα radial velocity variation is orb = 178.10 ± 0.08 min. We briefly discuss the evolutionary state of this system.

scholarly journals TOI-132 b: A short-period planet in the Neptune desert transiting a V = 11.3 G-type star★

2020 ◽  
Vol 493 (1) ◽  
pp. 973-985 ◽  
Author(s):  
Matías R Díaz ◽  
James S Jenkins ◽  
Davide Gandolfi ◽  
Eric D Lopez ◽  
Maritza G Soto ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Velocity Variation ◽  
Planetary Mass ◽  
Radial Velocity Variation ◽  
Short Period ◽  
Low Mass ◽  
Formation And Evolution ◽  
Level 1 ◽  
Atmospheric Mass

ABSTRACT The Neptune desert is a feature seen in the radius-period plane, whereby a notable dearth of short period, Neptune-like planets is found. Here, we report the Transiting Exoplanet Survey Satellite (TESS) discovery of a new short-period planet in the Neptune desert, orbiting the G-type dwarf TYC 8003-1117-1 (TOI-132). TESS photometry shows transit-like dips at the level of ∼1400 ppm occurring every ∼2.11 d. High-precision radial velocity follow-up with High Accuracy Radial Velocity Planet Searcher confirmed the planetary nature of the transit signal and provided a semi-amplitude radial velocity variation of 11.38 $^{+0.84}_{-0.85}$ m s−1, which, when combined with the stellar mass of 0.97 ± 0.06 M⊙, provides a planetary mass of 22.40$^{+1.90}_{-1.92}$ M⊕. Modelling the TESS light curve returns a planet radius of 3.42$^{+0.13}_{-0.14}$ R⊕, and therefore the planet bulk density is found to be 3.08$^{+0.44}_{-0.46}$ g cm−3. Planet structure models suggest that the bulk of the planet mass is in the form of a rocky core, with an atmospheric mass fraction of 4.3$^{+1.2}_{-2.3}$ per cent. TOI-132 b is a TESS Level 1 Science Requirement candidate, and therefore priority follow-up will allow the search for additional planets in the system, whilst helping to constrain low-mass planet formation and evolution models, particularly valuable for better understanding of the Neptune desert.

scholarly journals The Mysterious Nature of HS 2331+3905

2004 ◽  
Vol 194 ◽  
pp. 190-191 ◽  
Author(s):  
S. Aranjo-Betancor ◽  
B. T. Gänsicke ◽  
H.-J. Hagen ◽  
T. R. Marsh ◽  
J. Thorstensen ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Optical Spectroscopy ◽  
Orbital Period ◽  
White Dwarf ◽  
Large Amplitude ◽  
Cataclysmic Variable ◽  
Ccd Photometry ◽  
Velocity Variations

AbstractWe report the discovery of one unique cataclysmic variable drawn from the Hamburg Quasar Survey, HS 2331 + 3905. Follow-up observations obtained over three years unveiled a very unusual picture. The large amplitude 3.5 h radial velocity variations obtained from our optical spectroscopy is not the orbital period of the system, as one would normally expect. Instead, extensive CCD photometry strongly suggests that HS 2331 + 3005 is a short orbital period cataclysmic variable with Рorb = 81.09 min, containing a cold white dwarf which appears to exhibit ZZ Ceti pulsations.

scholarly journals XO-2b: a Prograde Planet with Negligible Eccentricity and an Additional Radial Velocity Variation

2011 ◽  
Vol 63 (6) ◽  
pp. L67-L71 ◽  
Author(s):  
Norio Narita ◽  
Teruyuki Hirano ◽  
Bun'ei Sato ◽  
Hiroki Harakawa ◽  
Akihiko Fukui ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Velocity Variation ◽  
Radial Velocity Variation

scholarly journals WASP-4 transit timing variation from a comprehensive set of 129 transits

2020 ◽  
Vol 496 (1) ◽  
pp. L11-L15 ◽  
Author(s):  
R V Baluev ◽  
E N Sokov ◽  
S Hoyer ◽  
C Huitson ◽  
José A R S da Silva ◽  
...  
Keyword(s):  
Conservative Treatment ◽  
Radial Velocity ◽  
Decay Rate ◽  
High Accuracy ◽  
Light Curves ◽  
Velocity Variation ◽  
Radial Acceleration ◽  
Radial Velocity Variation ◽  
Non Linear ◽  
Doppler Data

ABSTRACT We homogeneously reanalyse 124 transit light curves for the WASP-4 b hot Jupiter. This set involved new observations secured in 2019 and nearly all observations mentioned in the literature, including high-accuracy GEMINI/GMOS transmission spectroscopy of 2011–2014 and TESS observations of 2018. The analysis confirmed a non-linear transit timing variation (TTV) trend with $P/|\dot{P}|\sim \hbox{17-30}$ Myr (1σ range), implying only half of the initial decay rate estimation. The trend significance is at least 3.4σ in the aggressively conservative treatment. Possible radial acceleration due to unseen companions is not revealed in Doppler data covering seven years 2007–2014, and radial acceleration of −15 m s−1 yr−1 reported in a recent preprint by another team is not confirmed. If present, it is a very non-linear radial velocity variation. Assuming that the entire TTV is tidal in nature, the tidal quality factor $Q_\star ^{\prime }\sim \hbox{(4.5-8.5)}\times 10^4$ does not reveal a convincing disagreement with available theory predictions.

scholarly journals Swift/XRT Deep Galactic Plane Survey Discovery of a New Intermediate Polar Cataclysmic Variable, Swift J183920.1-045350

2021 ◽  
Vol 923 (2) ◽  
pp. 243
Author(s):  
Nicholas M. Gorgone ◽  
Patrick A. Woudt ◽  
David Buckley ◽  
Koji Mukai ◽  
Chryssa Kouveliotou ◽  
...  
Keyword(s):  
Orbital Period ◽  
Galactic Plane ◽  
Emission Lines ◽  
Cataclysmic Variable ◽  
Optical Photometry ◽  
X Ray ◽  
Common Features ◽  
Spin Period ◽  
Long Baseline

Abstract We report on the Swift/XRT Deep Galactic Plane Survey discovery and multiwavelength follow-up observations of a new intermediate polar (IP) cataclysmic variable, Swift J183920.1-045350. A 449.7 s spin period is found in XMM-Newton and NuSTAR data, accompanied by a 459.9 s optical period that is most likely the synodic, or beat period, produced from a 5.6 hr orbital period. The orbital period is seen with moderate significance in independent long-baseline optical photometry observations taken with the ZTF and SAAO telescopes. We find that the X-ray pulse fraction of the source decreases with increasing energy. The X-ray spectra are consistent with the presence of an Fe emission line complex with both local and interstellar absorption. In the optical spectra, strong Hα, H i, He i, and He ii emission lines are observed, all common features in magnetic CVs. The source properties are thus typical of known IPs, with the exception of its estimated distance of 2.26 − 0.83 + 1.93 kpc, which is larger than typical, extending the reach of the CV population in our Galaxy.

scholarly journals Pulsational Amplitudes of Cepheids – Their Application to Reveal Companions

2000 ◽  
Vol 176 ◽  
pp. 248-249
Author(s):  
László Szabados
Keyword(s):  
Radial Velocity ◽  
Velocity Variation ◽  
Radial Velocity Variation ◽  
Two Parameters

AbstractTwo parameters are defined involving the observed (peak-to-peak) amplitudes in U, B, V, and R photometric bands as well as that of the radial velocity variation. They are used to detect companions to Cepheids for a sample about 300 Galactic Cepheids.

scholarly journals The Detection of Triple Systems Through the Precession of the Nodes Effect

1983 ◽  
Vol 62 ◽  
pp. 120-124 ◽  
Author(s):  
T. Mazeh ◽  
M. Mayor
Keyword(s):  
Orbital Period ◽  
Velocity Variation ◽  
Mass Center ◽  
Period Ratio ◽  
Triple Systems ◽  
Close Pair ◽  
Radial Velocity Variation ◽  
A New Technique ◽  
A Current ◽  
Triple Stars

This paper is a report on a new technique for detecting close triple stars and on a current observational project with some preliminary results, using this method. The goal of the project is to discover new triple systems where the ratio between the long and the short orbital period is small. A system will be called a close triple system if its short orbital period is of several days.In most of the known triple stars (Fekel 1981), the period ratio is very large. This can be attributed to the fact that the wide orbit has been detected visually in most cases. In the few exceptions (e.g. λ Tau, Ebbighausen and Struve 1956), the wide orbit was discovered by detecting additional periodicity in the derived velocity of the close pair mass center γ As this small modulation is imposed on the large radial velocity variation associated with the orbit of the close pair, many triple systems could have escaped this kind of detection. Consequently, the present typical or averaged period ratio might be highly overestimated.

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