Search Publications
The K2 Light Curves and Stunted Outbursts of AC Cnc
Schlegel, E. M.; Honeycutt, R. K.
We describe two observations of the nova-like cataclysmic variable AC Cnc obtained with Kepler during its revamped second mission (K2). Using the K2 1 minute cadence mode, the data were obtained during campaigns 5 and 18. Campaign 5 (C05) lasted from ∼2015 April 27 to ∼2015 July 10, a total of 74.8 days, and yielded ∼106,000 measurements. Campaign…
An automated approach for photometer and dust mass calculation of the Crab nebula
Sauvage, Marc; Nehmé, Cyrine; Kassounian, Sarkis
Ample evidence exists regarding supernovae being a major contributor to interstellar dust. In this work, the deepest far-infrared observations of the Crab Nebula are used to revisit the estimation of the dust mass present in this supernova remnant. Images in filters between 70 and 500 µ m taken by the PACS and SPIRE instruments on-board of t…
A Long-term Photometric Variability and Spectroscopic Study of Luminous Blue Variable AF And in M31
Joshi, Yogesh C.; Misra, Kuntal; Gangopadhyay, Anjasha +2 more
We present a photometric and spectroscopic analysis of the Hubble-Sandage variable star AF And in M31. The data have been taken under the Nainital Microlensing Survey during 1998-2002, and follow-up observations were carried out until 2011. During this period, photometric observations in Cousins R and I bands were obtained for 169 nights spanning …
NuSTAR and XMM-Newton observations of SXP 59 during its 2017 giant outburst
Weng, Shan-Shan; Ge, Ming-Yu; Zhao, Hai-Hui
The Be X-ray pulsar (BeXRP) SXP 59 underwent a giant outburst in 2017 with a peak X-ray luminosity of 1.1 × 1038 erg s-1. We report on the X-ray behaviour of SXP 59 with the XMM-Newton and NuSTAR observations collected at the outburst peak, decay, and the low luminosity states. The pulse profiles are energy dependent, the pul…
The Circumstellar Envelope of the Semiregular Variable Star V CVn
Lamzin, S. A.; Rastorguev, A. S.; Safonov, B. S. +1 more
V CVn is a red semiregular variable star with an amplitude of its V-band brightness variations of ≈2 m . An unusually high amplitude of its polarization variability, up to 6%, a noticeable inverse correlation between polarization and total flux, and relative constancy of the angle of polarization distinguish this star from other semireg…
A Robust Ground-to-Image Transformation Algorithm and Its Applications in the Geometric Processing of Linear Pushbroom Images
Geng, Xun; Xu, Qing; Lan, Chaozhen +1 more
Linear array cameras are widely used in the fields of aerial and space remote sensing. The ground-to-image transformation plays a significant role in the geometric processing procedures of linear pushbroom images, which is time-consuming due to multiple iterative calculations. Moreover, the detectors of the linear array may exhibit a curved shape …
Fine-structure constant constraints on late-time dark energy transitions
Martins, C. J. A. P.; Prat Colomer, M.
We use recent astrophysical and local tests of the stability of the fine-structure constant, α, to constrain a particular phenomenological but physically motivated class of models in which the dark energy equation of state can undergo a rapid transition at low redshifts, perhaps associated with the onset of the acceleration phase. We set constrain…
Quest for the tertiary component in Cyg OB2 #5
Nazé, Yaël; Rauw, Gregor; Campos, Fran
Aims: The Cyg OB2 #5 system is thought to consist of a short-period (6.6 d) eclipsing massive binary orbited by an OB-star with a period of 6.7 yr; these stars in turn are orbited by a distant early B-star with a period of thousands of years. However, while the inner binary has been studied many times, information is missing on the other star…
Onset of a CME-Related Shock Within the Large-Angle Spectrometric Coronagraph (LASCO) Field of View
Fainshtein, V. G.; Egorov, Y. I.
We investigated the onset of a CME-related shock within the Large-Angle Spectrometric Coronagraph (LASCO) field of view (FOV). To detect the first moment of the shock onset, we found a CME on 17 July 2012 that formed at a relatively high altitude and moved with slow acceleration. We examined the possible mechanisms of shock generation. It was show…
Inflowing gas in the central parsec of M81
Devereux, Nick
Spectroscopic observations of the Seyfert 1/Liner nucleus of M81, obtained recently with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope(HST), have revealed an ultraviolet (UV)-visible spectrum rich with emission lines of a variety of widths, ionization potentials, and critical densities, including several in the UV that…