Search Publications
The nature of the Cygnus extreme B supergiant 2MASS J20395358+4222505
Lennon, D. J.; Herrero, A.; Comerón, F. +19 more
2MASS J20395358+4222505 is an obscured early B supergiant near the massive OB star association Cygnus OB2. Despite its bright infrared magnitude (Ks = 5.82) it has remained largely ignored because of its dim optical magnitude (B = 16.63, V = 13.68). In a previous paper, we classified it as a highly reddened, potentially extremely lumino…
Study on the magnetic field strength of NGC 300 ULX1
Li, Z. S.; Pan, Y. Y.; Zhong, J. X. +1 more
NGC 300 ULX1 is a pulsating ultraluminous X-ray source (PULX) with the longest spin period of $P\simeq 31.6\, \rm s$ and a high spin-up rate of $\dot{P}\simeq -5.56\times 10^{-7}\, \rm s\, s^{-1}$ that is ever seen in the confirmed PULXs. In this paper, the inferred magnetic field of NGC 300 ULX1 is $\sim 3.0\times 10^{14}\, \rm G$ using the recen…
A multiwavelength study of the H II region G347.600 + 00.211 and its effects on the surrounding medium
Molina Lera, J. A.; Gamen, R.; Cichowolski, S. +3 more
We present a multiwavelength investigation of the H II region G347.600+00.211, located at a distance of 7.9 kpc. We analyse the gas and dust properties aiming to disentangle the origin of the region as well as its role in the formation of new stars. G347.600 + 00.211 is very conspicuous at 1420 MHz and infrared wavelengths, showing an incomplete s…
The puzzling story of flare inactive ultra fast rotating M dwarfs. II. Searching for radial velocity variations
Ramsay, Gavin; Hakala, Pasi; Doyle, Lauren +2 more
Observations made using TESS revealed a sample of low-mass stars which show a periodic modulation on a period <0.2 d. Surprisingly, many of these ultra fast rotating (UFR) stars showed no evidence of flare activity which would be expected from such rapidly rotating stars. We present results from a spectroscopic survey of UFRs using the Nordic O…
A list of 49 new stellar twins from the Kepler catalogue of eclipsing binary stars
Bakış, Volkan; Yücel, Gökhan
49 new eclipsing twin binary candidates are identified and analysed based on the Kepler eclipsing binary light curves. Their colours and spectral types are calculated according to our classification. A comparison of the spectral type distribution of eclipsing twin binary systems showed that F-type twins dominate among others, which agrees well wit…
Photometric and spectroscopic study of the burst-like brightening of two Gaia-alerted young stellar objects
Moór, Attila; Ábrahám, Péter; Kóspál, Ágnes +18 more
Young stars show variability on different time-scales from hours to decades, with a range of amplitudes. We studied two young stars, which triggered the Gaia Science Alerts system due to brightenings on a time-scale of a year. Gaia20bwa brightened by about half a magnitude, whereas Gaia20fgx brightened by about two and half magnitudes. We analysed…
Decoding NGC 628 with radiative transfer methods
Popescu, C. C.; Pricopi, D.; Natale, G. +2 more
We present an axi-symmetric model for the ultraviolet (UV)-to-submillimetre (submm) images of the nearly face-on spiral galaxy NGC 628. It was calculated using a radiative transfer (RT) code, accounting for the absorption and re-emission of starlight by dust in the interstellar medium of this galaxy. The code incorporates emission from Polycyclic …
The rotation of planet-hosting stars
Feldmann, Robert; Helled, Ravit; Sibony, Yves
Understanding the distribution of angular momentum during the formation of planetary systems is a key topic in astrophysics. Data from the Kepler and Gaia missions allow to investigate whether stellar rotation is correlated with the presence of planets around Sun-like stars. Here, we perform a statistical analysis of the rotation period of 493 pla…
Monitoring observations of SMC X-1's excursions (MOOSE)-I. Programme description and initial high state spectral results
Clarkson, William I.; Dage, Kristen C.; Bahramian, Arash +8 more
SMC X-1 has exhibited three superorbital period excursions since the onset of X-ray monitoring beginning with the Rossi X-ray Timing Explorer's launch in 1995. TheNeutron star Interior Composition Explorer has recently probed a fourth observed excursion beginning in 2021 with our programme monitoring observations of SMC X-1's excursions (MOOSE). T…
A detailed star formation history for the extremely diffuse Andromeda XIX dwarf galaxy
Williams, Benjamin F.; Gilbert, Karoline M.; Dolphin, Andrew +3 more
We present deep imaging of the ultradiffuse Andromeda XIX dwarf galaxy from the Advance Camera for Surveys on the Hubble Space Telescope which resolves its stellar populations to below the oldest main-sequence turn-off. We derive a full star formation history for the galaxy using MATCH, and find no evidence of star formation in the past 8 Gyr. We …