Short-Period Radial-Velocity Variation of 48 Librae.

1963 ◽  
Vol 137 ◽  
pp. 1310 ◽  
Author(s):  
Adela E. Ringuelet-Kaswalder
2020 ◽  
Vol 493 (1) ◽  
pp. 973-985 ◽  
Author(s):  
Matías R Díaz ◽  
James S Jenkins ◽  
Davide Gandolfi ◽  
Eric D Lopez ◽  
Maritza G Soto ◽  
...  

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.


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

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 ◽  
...  

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.


2000 ◽  
Vol 176 ◽  
pp. 248-249
Author(s):  
László Szabados

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.


1988 ◽  
Vol 126 ◽  
pp. 675-676
Author(s):  
Robert D. Mathieu ◽  
David W. Latham

Mathieu et al. (1986) have completed an extensive radial-velocity survey of over 100 late-type stars in M 67 with V < 12.8. The spatial distributions of the spectroscopic binaries and single stars (i.e. those stars without detected radial-velocity variation; many of these are undoubtedly binaries, albeit with lower secondary masses) are shown in Fig. 1. The distribution of the binaries is notably more centrally concentrated than the single stars. The two observed distributions derive from distinct parent distributions at the 98% confidence level. The projected half-mass radius of the binaries is 0.9 pc; the half-mass radius of the single stars is 2.4 pc. Indeed, 77% of the binaries lie within the single-star half-mass radius.


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