Sumanta Kumar SahooCentrum Astronomiczne im. M. Kopernika PAN · Department of Astrophysics
Sumanta Kumar Sahoo
PhD in Astronomy
About
24
Publications
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94
Citations
Citations since 2017
Introduction
Additional affiliations
October 2018 - present
October 2018 - present
Position
- Research Project Student
Description
- ARDASTELLA Research Group
August 2017 - July 2018
Education
July 2013 - April 2018
Publications
Publications (24)
We present an update on the variable star survey performed on the TESS 30 min Full Frame Image (FFI) data reported by our first two papers in this series. This update includes a contamination analysis in order to identify false positives and analysis of the TESS 10 min FFI data collected during Years 3 and 4 of the mission. We clarify the variabili...
We present an update on the variable star survey performed on the TESS 30 min Full Frame Image (FFI) data reported by our first two papers in this series. This update includes a contamination analysis in order to identify false positives and analysis of the TESS 10 min FFI data collected during Years 3 and 4 of the mission. We clarify the variabili...
TIC033834484 and TIC309658435 are long-period pulsating subdwarf B star, which were observed extensively (675 and 621 days, respectively) by the Transiting Exoplanet Survey Satellite (TESS). The high-precision photometric light curve reveals the presence of more than 40 pulsation modes including both stars. All the oscillation frequencies that we f...
We present results of a Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed in years 1 and 3 of the TESS mission, during which the southern ecliptic hemisphere was targeted. We describe the TESS data used and the details of the search method. For many of the targets, we use unpublished...
We present results of a Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed in years 1 and 3 of the TESS mission, during which the southern ecliptic hemisphere was targeted. We describe the TESS data used and the details of the search method. For many of the targets, we use unpublished...
We present the list of variable stars we found in the Kepler superstamp data covering approximately 9' from the central region of NGC 6791. We classified the variable stars based on the variability type and we established their cluster membership based on the available Gaia Early Data Release 3 astrometry, by means of the Bayesian Gaussian mixture...
TIC 137608661/TYC 4544-2658-1/FBS 0938+788 is a new sdBV+dM reflection-effect binary discovered by the TESS space mission with an orbital period of 7.21 hours. In addition to the orbital frequency and its harmonics, the Fourier transform of TIC 137608661 shows many g-mode pulsation frequencies from the sdB star. The amplitude spectrum is particular...
TIC137608661/TYC4544-2658-1/FBS0938+788 is a new sdBV+dM reflection-effect binary discovered by the TESS space mission with an orbital period of 7.21 hours. In addition to the orbital frequency and its harmonics, the Fourier transform of TIC137608661 shows many g-mode pulsation frequencies from the sdB star. The amplitude spectrum is particularly s...
We report results of our analysis of the Kepler superaperture LC data of the open cluster NGC6791 to search for pulsating sdB stars. We checked all pixels and we found only three sdB stars to be pulsating, KIC2569576 (B3), KIC2438324 (B4) and KIC2437937 (B5). These stars were known to be pulsators before, though we extended data coverage detecting...
We report results of our analysis of the Kepler superaperture LC data of the open cluster NGC 6791 to search for pulsating sdB stars. We checked all pixels and we found only three sdB stars to be pulsating, KIC 2569576 (B3), KIC 2438324 (B4) and KIC 2437937 (B5). These stars were known to be pulsators before, though we extended data coverage detect...
Context. We present photometric and spectroscopic analyses of gravity ( g -mode) long-period pulsating hot subdwarf B (sdB) stars, also called V1093 Her stars, observed by the TESS space telescope in both 120 s short-cadence and 20 s ultra-short-cadence mode during the survey observation and the extended mission of the southern ecliptic hemisphere....
We present photometric and spectroscopic analyses of gravity (g-mode) long-period pulsating hot subdwarf B (sdB) stars. We perform a detailed asteroseismic and spectroscopic analysis of five pulsating sdB stars observed with {\it TESS} aiming at the global comparison of the observations with the model predictions based on our stellar evolution comp...
We report the results of our search for pulsating subdwarf B stars in Full Frame Images collected during Year 2 of the TESS mission and covering the northern ecliptic hemisphere. This is a continuation of our effort we presented in Paper I. We found 13 likely new pulsating subdwarf B stars, 10 pulsating candidates that are identified as other hot s...
The results of the evolutionary modelling of subdwarf B stars are presented. For the first time, we explore the core and near-core mixing in subdwarf B stars using new algorithms available in the mesa code: the predictive mixing scheme and the convective pre-mixing scheme. We show how both methods handle problems related to the determination of the...
We report the results of our search for pulsating subdwarf B stars in Full Frame Images collected during Year 2 of the TESS mission and covering the northern ecliptic hemisphere. This is a continuation of our effort we presented in Paper I. We found 13 likely new pulsating subdwarf B stars, 10 pulsating candidates that are identified as other hot s...
Results of evolutionary modelling of subdwarf B stars are presented. For the first time, we explore the core and near-core mixing in the subdwarf B stars using new algorithms available in the MESA code: the predictive mixing scheme and the convective premixing scheme. We show how both methods handle the problems with determination of convective bou...
We report the results of our search for pulsating subdwarf B stars in Full Frame Images, sampled at 30 min cadence and collected during Year 1 of the TESS mission. Year 1 covers most of the southern ecliptic hemisphere. The sample of objects we checked for pulsations was selected from a subdwarf B stars database available to public. Only two positi...
We report the results of our search for pulsating subdwarf B stars in Full Frame Images, sampled at 30 min cadence and collected during Year 1 of the TESS mission. Year 1 covers most of the southern ecliptic hemisphere. The sample of objects we checked for pulsations was selected from a subdwarf B stars database available to public. Only two positi...
We report on the detection of pulsations of three pulsating subdwarf B stars observed by the TESS satellite and our results of mode identification in these stars based on an asymptotic period relation. SB 459 (TIC 067584818), SB 815 (TIC 169285097) and PG 0342+026 (TIC 457168745) have been monitored during single sectors resulting in 27 days covera...
We report on the detection of pulsations of three pulsating subdwarf B stars observed by the TESS satellite and our results of mode identification in these stars based on an asymptotic period relation. SB 459 (TIC 067584818), SB 815 (TIC 169285097) and PG 0342+026 (TIC 457168745) have been monitored during single sectors resulting in 27 days covera...
Transiting Exoplanet Survey Satellite (TESS) observations show CD−28° 1974 to be a gravity(g)-mode-dominated hybrid pulsating subdwarf B (sdBV) star. It shows 13 secure periods that form an ℓ = 1 asymptotic sequence near the typical period spacing. Extraordinarily, these periods lie between 1500 and 3300 s, whereas typical $\ell = 1\, g$ modes in s...
Final presentation of the summer internship project ”Episodic Accretion in V2493 CYG”. In the presentation, basics of low mass star formation, the mass accretion process, the observational and data analysis processes during the project work and the findings have been described.
Context.The investigations of the photometric and spectral variability of Pre Main Sequence(PMS) stars are essential to a better understanding of the early phases of stellar evolution because this critical early stage of star determines its mass and path of evolution.Especially V2493 Cyg is a special type of star that only few numbers of stars have...
In this paper I briefly reviewed some of the fundamental concepts of Cosmology. In the beginning some basic concepts like the isotropy and homogeneity of the universe on a large scale, Olber Paradox and its resolution, the expansion of the space-time in terms of red shift and Hubble's law have been explained. I derived the equation of curvature of...
Projects
Projects (2)
This Project is inclined towards the investigation of star formation in extreme conditions like in the intergalactic medium, in tidal arms of colliding galaxies, star formation due to the Ram Pressure Stripping, triggered star formation in satellite galaxies and in the inter stellar medium of the AGNs due to the effect of radio jets. The second objective of this project is to understand how such triggered star formation processes are different from the normal galactic star formation like in our Milkyway.
