Search Publications
Mass function of understudied open clusters NGC 2254 and Mayer 2
Kowshik, Krishna Kumar; Sujatha, S.; Komala, S. +1 more
The results of the CCD photometric UBVRI observations of the open clusters NGC 2254 and Mayer 2 are presented in this article. These clusters were observed using the 2-metre Himalayan Chandra Telescope at Hanle, India. NGC 2254 is located in the direction of Monoceros constellation at a distance of 2.57 ± 0.2 kpc and Mayer 2 is located in the dire…
Role of the companion lensing galaxy in the CLASS gravitational lens B1152+199
Zhang, L.; Zhang, M.; Yuan, Q. +1 more
We reinvestigate the Cosmic Lens All-Sky Survey (CLASS) gravitational lens B1152+199 using archived Hubble Space Telescope (HST) data and Very Long Baseline Interferometry (VLBI) data. A consistent luminosity ratio within effective radius between the host galaxy and the X-galaxy is measured from HST tri-band images, which leads to a mass ratio bet…
Dione's Thermal Inertia and Bolometric Bond Albedo Derived from Cassini/CIRS Observations of Solar Eclipse Ingress
Spencer, John R.; Howett, Carly J. A.
On 2010 May 18 Cassini's Composite Infrared Spectrometer (CIRS) observed Dione's leading hemisphere as its surface went into solar eclipse. Surface temperatures derived from each of CIRS' focal plane 3 (FP3, 600-1100 cm-1) show a rapid decrease in Dione's surface temperature upon eclipse ingress. This change was compared to the model su…
Semi-detached double-lined eclipsing binaries with Gaia DR3 data
Malkov, O. Yu.; Grinenko, A. D.; Sachkov, A. M.
Semi-detached double-lined eclipsing binaries (SD DLEB) play an important role in our understanding of basic properties of interacting binaries. We have collected data on semi-detached systems with available light and radial velocity curve solutions, and have compiled the most comprehensive list of SD DLEB, containing astrophysical and orbital par…
Study of Intra-Day Flux Distributions of Blazars Using XMM-Newton Satellite
Gaur, Haritma; Wani, Kiran
We present a study of the flux distribution of a sample of 15 Intermediate and Low-energy peaked blazars using XMM-Newton observations in a total of 57 epochs on short-term timescales. We characterise the X-ray variability of all of the light curves using excess fractional variability amplitude and found that only 24 light curves in 7 sources are …
Magnetosheath Filamentary Structures Driven by Foreshock Energetic Ions
Wei, Xinhua; Ma, Yuduan; Yang, Junying +1 more
Previous simulation studies have revealed the formation of magnetosheath filamentary structures by foreshock energetic ions. We report Cluster and Double Star observations of three such events triggered by a foreshock bubble, a hot flow anomaly and a traveling foreshock, respectively. In each case, in association with the onset of foreshock energe…
OGLE-BLG504.12.201843: a possible extreme dwarf nova
Strader, Jay; Udalski, Andrzej; Prieto, Jose L. +5 more
We present the analysis of existing optical photometry and new optical spectroscopy of the candidate cataclysmic variable star OGLE-BLG504.12.201843. As was shown previously, this object has an orbital period of 0.523419 d and exhibits year-long outbursts with a mean period of 973 d. Using digitized photographic archives, we show that the earliest…
Exploring the region encompassing γ Cygni SNR and MAGIC J2019+408 with the GMRT at 325 and 610 MHz
Paredes, J. M.; Strzys, M.; Ishwara-Chandra, C. H. +2 more
Context. γ Cygni is a young supernova remnant located in the Cygnus region. MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes detected TeV emission (MAGIC J2019+408) to the north-west of this remnant, ~5' from its border.
Aims: We want to identify the radio sources within the region encompassing γ Cygni and MAGIC J2019+408 to shed …
Comparing the Sun Watcher Using Active Pixel System Detector and Image Processing Instrument to the Atmosphere Imaging Assembly Instrument Through Measurements of Polar Coronal Holes
West, Matthew J.; Pesnell, W. Dean; Kirk, Michael S. F. +2 more
The PRoject for OnBoard Autonomy 2/Sun Watcher using Active pixel system detector and image Processing (PROBA2/SWAP) instrument images the full-disk extreme ultraviolet (EUV) Sun using a complementary metal-oxide semiconductor active-pixel sensor (CMOS-APS) detector with a filter centered on a 174 Å passband at a cadence of one to two minutes. In …
Detection of Equatorial Plasma Velocity Modulations Associated With Planetary Period Oscillations in Saturn's Magnetosphere
Wilson, R. J.; Cowley, S. W. H.; Provan, G. +1 more
We analyze a database of 8920 measurements of thermal ion vector velocities obtained by the Cassini CAPS/IMS instrument in the near-equatorial (±10° latitude) region of Saturn's magnetosphere in the radial range of 5.5-21.5 Saturn radii (RS) for the presence of modulations due to planetary period oscillations (PPOs). The data span 2004-…