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The star HD 147379 was recently announced as a host of a low-mass exoplanet by Reiners et al. (2017). That announcement included a discussion of the possible detection of a periodic signal in the radial velocity observations around 21.1…

Earth and Planetary Astrophysics · Physics 2018-01-08 Joshua Pepper

HD 142990 (V 913 Sco; B5 V) is a He-weak star with a strong surface magnetic field and a short rotation period ($P_{\rm rot} \sim 1$ d). While it is clearly a rapid rotator, recent determinations of $P_{\rm rot}$ are in formal disagreement.…

Solar and Stellar Astrophysics · Physics 2019-05-22 M. Shultz , Th. Rivinius , B. Das , G. A. Wade , P. Chandra

We have employed an extensive new timeseries of Stokes I and V spectra obtained with the ESPaDOnS spectropolarimeter at the 3.6-m Canada-France-Hawaii Telescope to investigate the physical parameters, chemical abundance distributions and…

Solar and Stellar Astrophysics · Physics 2015-06-18 I. Yakunin , G. Wade , D. Bohlender , O. Kochukhov , V. Tsymbal , MiMeS Collaborators

Using patterns in the oscillation frequencies of a white dwarf observed by K2, we have measured the fastest rotation rate, 1.13(02) hr, of any isolated pulsating white dwarf known to date. Balmer-line fits to follow-up spectroscopy from the…

We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of $1.28 \pm 0.18$ MJ, radius of $1.53_{-0.047}^{+0.046}$ RJ, and an orbital period of $2.7347749 \pm 0.0000039$ days. The bright host star (HD33643; KELT-7) is an…

HR 5907 (HD 142184) stands out among magnetic OB stars for its rapid rotation, exceptionally hard X-ray emission, and strong magnetic field. High-frequency (>5 GHz) radio emission from the star exhibits an approximately flat spectrum that…

Solar and Stellar Astrophysics · Physics 2025-01-22 Ayan Biswas , Barnali Das , James A. Barron , Gregg A. Wade , Gonzalo Holgado

The O8f?p star HD 108 is implied to have experienced the most extreme rotational braking of any magnetic, massive star, with a rotational period $P_{\rm rot}$ of at least 55 years, but the upper limit on its spindown timescale is over twice…

Solar and Stellar Astrophysics · Physics 2017-05-10 M. Shultz , G. A. Wade

HH 50138 is one of the brightest B[e] stars at a distance of $\sim$ 380 pc with strong infrared excess. The star was observed in [O I] 63 $\mu$m and [C II] 158 $\mu$m with high velocity resolution with upGREAT on SOFIA. The velocity…

Solar and Stellar Astrophysics · Physics 2018-10-10 G. Sandell , C. Salyk , M. van den Ancker , W. -J. de Wit , E. Chambers , R. Güsten , H. Wiesemeyer , H. Richter

We report the detection, made using ALMA, of the 92 GHz continuum and hydrogen recombination lines (HRLs) H40$\alpha$, H42$\alpha$, and H50$\beta$ emission toward the ionized wind associated with the high-mass young stellar object…

We present the discovery of a long-period, rapidly oscillating Ap star, HD177765. Using high-resolution time-series observations obtained with UVES at the ESO VLT telescope, we found radial velocity variations with amplitudes 7-150 m/s and…

Solar and Stellar Astrophysics · Physics 2015-06-03 D. Alentiev , O. Kochukhov , T. Ryabchikova , M. Cunha , V. Tsymbal , W. Weiss

We present time-series spectroscopy of the rapidly oscillating Ap star HR 3831. This star has a dominant pulsation period of 11.7 minutes and a rotation period of 2.85 days. We have analysed 1400 intermediate-resolution spectra of the…

Astrophysics · Physics 2015-06-24 I. K. Baldry , T. R. Bedding

Using the Tremaine-Weinberg method, we measure the speed of the HI bar seen in the disk of NGC 3741. NGC 3741 is an extremely gas rich galaxy with an {H\,{\sc i}} disk which extends to about 8.3 times its Holmberg radius. It is also highly…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Arunima Banerjee , Narendra Nath Patra , Jayaram N. Chengalur , Ayesha Begum

We present the optical spectroscopic study based on 41 spectra of 4 Her and 32 spectra of 88 Her, obtained over a period of 6 months. We estimate the rotational velocity of these stars from He{\sc i} lines in the blue spectral region…

Solar and Stellar Astrophysics · Physics 2016-04-22 Bhat S Shruthi , K T Paul , Subramaniam Annapurni , Mathew Blesson

We find that the orbital period (2.4 hours), eccentricity (0.09), dipole magnetic field strength (6.9 x 10^9 Gauss) and spin period (22 ms) of the new highly relativistic double neutron star system PSR J0737-3039 can all be consistently…

Astrophysics · Physics 2009-11-10 J. D. M. Dewi , E. P. J. van den Heuvel

The gamma-ray binary HESS J0632+057 consists of a Be star and an undetected compact object in a $\sim$317 day orbit. The interpretation of the emission from this system is complicated by the lack of a clear orbital solution, as two…

High Energy Astrophysical Phenomena · Physics 2024-11-28 Natalie Matchett , Brian van Soelen

HD50138 is a Herbig B[e] star with a circumstellar disc detected at IR and mm wavelength. Its brightness makes it a good candidate for NIR interferometry observations. We aim to resolve, spatially and spectrally, the continuum and hydrogen…

Solar and Stellar Astrophysics · Physics 2018-06-27 M. Koutoulaki , R. Garcia Lopez , A. Natta , A. Caratti o Garatti , D. Coffey , J. Sanchez-Bermudez , T. P. Ray

We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning two years. Using the transit photometry, we determine the stellar and planetary radii and the photometric…

The variable star V39 in the field of IC 1613 is discussed in the light of the available photometric and new spectroscopic data. It has strong emission Balmer lines, and the observed characteristics could be explained by a W Vir pulsating…

Astrophysics · Physics 2009-11-07 L. Mantegazza , E. Antonello , D. Fugazza , S. Covino , G. Israel

A team involved in APOGEE, one of the Sloan Digital Sky Survey III programs, recently announced the discovery of two rare rigidly rotating magnetosphere stars, HD345439 and HD23478. Near-infrared spectra of these objects revealed…

Solar and Stellar Astrophysics · Physics 2017-04-05 S. Hubrig , A. F. Kholtygin , M. Schöller , I. Ilyin

We report about HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at 7 epochs spanning a time…

Solar and Stellar Astrophysics · Physics 2023-02-08 Gautier Mathys , Viktor Khalack , Oleksandr Kobzar , Francis LeBlanc , Pierre L. North