Search Publications
Theoretical mass-luminosity relations in Gaia G-band
Malkov, Oleg; Kovaleva, Dana; Zhukov, Aleksandr +1 more
We have analyzed the retrieval of the relation between mass and absolute Gaia G magnitude as obtained from theoretical models by Bressan et al. (Mon. Not. R. Astron. Soc. 427:127, 2012) for the stars of different luminosity classes. For subgiant and main-sequence stars, we provide approximate analytical direct and inverse relations based on the mo…
Timing and spectral studies of the X-ray pulsar 2S 1417–624 during the outburst in 2021
Mandal, Manoj; Pal, Sabyasachi
We study the timing and spectral properties of the X-ray pulsar 2S 1417–624 during the recent outburst in January 2021 based on the Neutron Star Interior Composition Explorer (NICER) observation. We also used some early data from the 2018 outburst to compare different temporal and spectral properties. The evolution of the spin period and pulsed fl…
Variation of ionospheric plasma density during the annular solar eclipse on December 26, 2019
Palit, Sourav; Kundu, Subrata; Chowdhury, Swati +2 more
The annular solar eclipse of the previous decade that occurred on December 26, 2019, was mostly visible from most Asian countries, including India. In this manuscript, we present the variation of ionospheric plasma density profiles at different heights during the eclipse and non-eclipse days. We use both the ground- and space-based instruments to …
Active region and flare ribbon properties associated with X-class flares and CMEs of solar cycle 24
Moon, Y. -J.; Shanmugaraju, A.; Lim, Daye +4 more
The solar eruptive events and their origin are important in the context of forecasting their occurrence and their effects on the space and the earth. In this paper, a set of 45 X-class flare-associated coronal mass ejections (CMEs) and their source region characteristics are analysed. The X-ray flares and white light CMEs were observed by GOES and…
Interacting planetary nebulae III: verification and galactic population based on the measurements of Gaia EDR3
Ali, A.; Mindil, A.; Mohery, M. +1 more
The phenomenon of interaction between planetary nebulae (PNe) and the interstellar medium (ISM) is one of the significant issues in the field of astrophysics. The main objective of this paper is to verify the interaction process for objects that have been known as interacting PNe (IPNe) in the literature. This study is based on parallax and proper…
Constructing a global ionospheric TEC map with a high spatial and temporal resolution by spherical harmonic functions
Xiong, Bo; Wang, Yuqing; Li, Xiaolin +2 more
The Massachusetts Institute of Technology (MIT) Haystack Observatory provides the ionospheric Total Electron Content (TEC) data with a temporal resolution of 5 minutes and limited spatial coverage, as they do not provide data where there are no TEC measurements. To improve the spatial coverage of MIT-TEC, we have proposed an approach for construct…
Age-velocity relations with GALEXF U V
Murray-Clay, Ruth; Crandall, Sara; Smith, Graeme H. +3 more
A relationship between chromospheric activity and age is calibrated for FGK dwarf stars using GALEX
Mass evaluation for red giant stars based on the spectroscopically determined atmospheric parameters
Takeda, Yoichi
The mass (
A radio continuum study of NGC 2082
Filipović, M. D.; Dai, S.; Barnes, L. +2 more
We present radio continuum observations of NGC 2082 using ASKAP, ATCA and Parkes telescopes from 888 MHz to 9000 MHz. Some 20 arcsec from the centre of this nearby spiral galaxy, we discovered a bright and compact radio source, J054149.24–641813.7, of unknown origin. To constrain the nature of J054149.24–641813.7, we searched for transient events …
XMM-Newton and Swift observations of the Seyfert 1 AGN NGC 5940
Adegoke, Oluwashina K.
Probing the physics of the accretion flow around active galactic nuclei (AGN) is crucial to understanding their emission mechanisms as well as being able to constrain the geometrical and variability properties of the different regions around them. The soft X-ray excess – usually observed below