We present periodicity search analyses on the γ -ray light curve of the TeV blazar PKS 1510-089 observed by the Fermi Large Area Telescope. We report the detection of two transient quasi-periodic oscillations: A 3.6-d QPO ...

The ancient people used to look up at stars for the purpose of making an authentic calendar. People from antiquity were interested to know the actual juncture to sow seedlings and when to expect rains. Eventually the ...

Quasi-periodic X-ray eruptions (QPEs) are a recently discovered phenomenon, the nature of which remains unclear. Based on their discovery in active galactic nuclei (AGNs), explanations related to an AGN accretion disk or ...

A photometric and spectroscopic investigation is performed on five W Ursae Majoris eclipsing binaries J015818.6 +260247 (hereinafter as J0158b), J073248.4+405538 (hereinafter as J0732), J101330.8+494846 (hereinafter ...

We present a comparative study of the physical properties of a homogeneous sample of 144 Narrow line Seyfert 1 (NLSy1) and 117 Broad-line Seyfert 1 (BLSy1) galaxies. These two samples are in a similar luminosity and ...

We report the first study to characterize intranight variability of the blazar class from the perspective of (rest-frame) ultraviolet (UV) emission. For this, we carried out intranight optical monitoring of 14 flat-spectrum ...

We report results of optical imaging and low-resolution spectroscopic monitoring of supernova (SN) 2017iro that occurred in the nearby (∼31 Mpc) galaxy NGC 5480. The He I λ5876 feature present in the earliest spectrum (−7 ...

NGC 7789 is a ∼1.6 Gyr old, populous open cluster located at ∼2000 pc. We characterize the blue straggler stars (BSS) of this cluster using the Ultraviolet (UV) data from the UVIT/AstroSat. We present spectral energy ...

The 4m international liquid mirror telescope (ILMT) installation activities have recently been completed at the Devasthal observatory (Uttarakhand, India). The ILMT will perform continuous observa tion of a narrow strip ...

Stars are formed by gravitational collapse, spontaneously or, in some cases under the constructive influence of nearby massive stars, out of molecular cloud cores. Here we present an observational diagnosis of such ...