We present observations of the active M-dwarf binary AT Mic (dM4.5e+dM4.5e) obtained with the orbital observatory AstroSat. During 20 ks of observations, in the far-ultraviolet (130–180 nm) and soft X-ray (0.3–7 keV) spectral ...

Using data from observations made with XMM–Newton, we present an X-ray analysis of two Wolf–Rayet (WR) binaries: V444 Cyg and CD Cru. The X-ray light curves show the phase-locked variability in both binaries, where the ...

Using XMM-Newton observations, we investigate properties of a flare from the very active but poorly known stellar system 47 Cas. The luminosity at the peak of the flare is found to be 3.54 × 10 ³⁰ erg s⁻¹, which is ∼2 times ...

We present X-ray intraday variability and power spectral density (PSD) analyses of the longest 23 pointed XMM–Newton observations of the blazar 3C 273 that were taken during 2000–2021. These good time intervals contain ...

We present an extensive study of 72 archival Chandra light curves of the high-frequencypeaked type blazar Mrk 421, the first strong extragalactic object to be detected at TeV energies. Between 2000 and 2015, Mrk 421 often ...

We present a detailed X-ray analysis and imaging of stellar coronae of five coronally connected eclipsing binaries, namely, 44 Boo, DV Psc, ER Vul, XY UMa, and TX Cnc. Both components of these binaries are found to ...

The yake effects in the 56 cm and the 38 cm pyrex mirrors of the Uttar Pradesh State Observatory is described. Similarly effects elsewhere are also discussed.

The Odd Radio Circles are newly identified diffuse radio sources at ∼1 GHz frequency, with edge-brightened nearly circular morphology, which is remarkably similar to supernova remnants although a physical association with ...

It is found that the differential extinction ∆E(B - V) in open clusters, which may be due to the presence of gas and dust, decreases systematically with the age of the cluster. Consequently we can infer that the average ...

Bright-rimmed clouds (BRCs), illuminated and shaped by nearby OB stars, are potential sites of recent/ongoing star formation. Here we present an optical and infrared photometric study of three BRCs: BRC 5, BRC 7 and BRC ...