Search Publications
Surface activity of rapidly rotating stars from simultaneous X-ray and UV observations with AstroSat
Sairam, Lalitha; Pathak, Utkarsh; Singh, Kulinder Pal
Our study focuses on analysing the coronal, transition and chromospheric activity of four rapidly rotating stars located within 50 pc in the solar neighborhood. We have used the multi-wavelength capabilities of AstroSat to investigate the outer atmospheres of AB Dor, BO Mic, DG CVn and GJ 3331. These stars, classified as M and K type active stars,…
Investigating star-formation activity in Sh 2-61 H II region
Pandey, Rakesh; Sharma, Saurabh; Dewangan, Lokesh +4 more
Using multi-wavelength data sets, we studied the star-formation activity in H II region Sh 2-61 (hereafter S61). We identified a clustering in the region and estimated the membership using the Gaia proper motion data. The physical environment of S61 is inspected using infrared to radio wavelength images. We also determined the Lyman continuum flux…
Diving deep into the milky way using anti-reflection coatings for astronomical CCDs
Seabroke, George M.; Aggarwal, Anmol; Mittal, Ashi +1 more
We report two anti-reflection (AR) coatings that give better quantum efficiency (QE) than the existing AR coating on the Gaia astrometric field (AF) charged coupled devices (CCDs). Light being the core of optical astronomy is extremely important for such missions, therefore, the QE of the devices that are used to capture it should be substantially…
Revisiting the old end of the Milky Way open cluster age function
Piatti, Andrés E.
Age distribution of the open cluster system is a key piece of information to decipher the star-formation history of the milky way disk. Recently, a remarkable earlier drop of its older end was found, which caught our attention. Precisely, we analysed in detail the population of open clusters older than 1 Gyr located inside a circle of 2.0 kpc from…
Fundamental parameters and stellar mass function of four open clusters close to the galactic plane
Kowshik, Krishna Kumar; Sujatha, S.; Routh, Swati
In the context of understanding star formation in the galactic plane, we present the results from the analysis of four young open clusters using archival data from Gaia Data Release 3, the Two-Micron All Sky Survey (2MASS) and Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). The open clusters—[BDB2003]G085.25‑00.02, [BDS2003]48, …
Infrared polarisation study of Lynds 1340: A case of RNO 8
Ganesh, Shashikiran; Rai, Archita
This paper describes the polarisation study of a Lynds cloud, LDN 1340,
Detection of polycyclic aromatic hydrocarbons on a sample of comets
Bhardwaj, Anil; Ramachandran, R.; Hill, H. +6 more
We present the spectral properties of a selection of comets from both the Jupiter family and Oort cloud in the ultraviolet (UV) and mid-infrared (IR) wavelength regions. Spectroscopic measurements are retrieved from public archival data of the International Ultraviolet Explorer (IUE) and Hubble Space Observatory (HST) in the near-UV (NUV) and far-…
A comprehensive photometric and kinematical characteristic of the newly discovered QCs clusters with Gaia EDR3
Elsanhoury, W. H.; Haroon, A. A.; Amin, Magdy Y. +1 more
This study reports the first comprehensive astrometric, photometric, and kinematical analysis of four newly discovered open clusters; namely QC1, QC2, QC3, and QC4, using astrometric and photometric data from the most recent Gaia EDR3 for
Deep V and I CCD photometry of young star cluster NGC 1893 with the 3.6m DOT
Pandey, S. B.; Panwar, Neelam; Kumar, Amit
Young star clusters consisting of massive stars are the ideal sites to study the star formation processes and influence of massive stars on the subsequent star formation. NGC 1893 is a young star cluster associated with the HII region Sh2-236. It contains about five 'O'-type stars and several early 'B'-type stars. It is located at a moderate dista…
Optical observations of star clusters NGC 1513 and NGC 4147; white dwarf WD 1145+
Yadav, R. K. S.; Pandey, S. B.; Sharma, Saurabh +3 more
The UBVRI CCD photometric data of open star cluster NGC 1513 are obtained with the 3.6-m Indo-Belgian Devasthal optical telescope (DOT). Analyses of the GAIA EDR3 astrometric data have identified 106 possible cluster members. The mean proper motion of the cluster is estimated as