Zobrazeno 1 - 10
of 58
pro vyhledávání: '"HEMA, B. P."'
Determining the He/H ratio in cool stars presents a fundamental astrophysical challenge. While this ratio is established for hot O and B stars, its extrapolation to cool stars remains uncertain due to the absence of helium lines in their observed spe
Externí odkaz:
http://arxiv.org/abs/2408.03041
Autor:
Pandey, Gajendra, Hema, B. P., Reddy, Arumalla B. S., Astrophysics, Indian Institute of, Bangalore, Karnataka, India
Surface abundances of 14 (11 majority class and 3 minority class) R Coronae Borealis stars (RCBs) along with the final flash object, V4334 Sgr (Sakurai's object) are revised based on their carbon abundances measured from the observed C2 bands; note t
Externí odkaz:
http://arxiv.org/abs/2108.02736
Autor:
Hema, B. P., Pandey, Gajendra
In this work, the helium-enhancement (He-enhancement) in the lithium-rich (Li-rich) K-giant HD 77361 is investigated using the strengths of the MgH band and the MgI lines. The detailed abundance analysis and also the synthesis of the MgH band and the
Externí odkaz:
http://arxiv.org/abs/2010.03998
The helium-enriched (He-enriched) metal-rich red giants of Omega Centauri, discovered by Hema and Pandey using the low-resolution spectra from the Vainu Bappu Telescope (VBT) and confirmed by the analyses of the high-resolution spectra obtained from
Externí odkaz:
http://arxiv.org/abs/2005.06807
High-resolution optical spectra are analyzed for two of the four metal rich mildly hydrogen-poor or helium-enhanced giants discovered by Hema and Pandey (2014) along with their comparison normal (hydrogen-rich) giants of Omega Cen. The strengths of t
Externí odkaz:
http://arxiv.org/abs/1807.10813
Autor:
Hema, B. P., Pandey, Gajendra, Kamath, Devika, Rao, N. Kameswara, Lambert, David, Woolf, Vincent M.
Abundance analyses of the two newly discovered R Coronae Borealis (RCB) stars ASAS-RCB-8 and ASAS-RCB-10 were conducted using high-resolution optical spectra and model atmospheres. Their chemical compositions place the pair among the majority class o
Externí odkaz:
http://arxiv.org/abs/1707.01268
Autor:
Balona, L. A., Engelbrecht, C. A., Joshi, Yogesh C., Joshi, S., Sharma, K., Semenko, E., Pandey, G., Chakradhari, N. K., Mkrtichian, David, Hema, B. P., Nemec, J. M.
The hot $\gamma$~Doradus stars have multiple low frequencies characteristic of $\gamma$~Dor or SPB variables, but are located between the red edge of the SPB and the blue edge of the $\gamma$~Dor instability strips where all low-frequency modes are s
Externí odkaz:
http://arxiv.org/abs/1606.06426
Autor:
Hema, B. P., Pandey, Gajendra
In this letter, the results of our low-resolution spectroscopic survey for identifying the hydrogen-deficient (H-deficient) stars in the red giant sample of the globular cluster Omega Cen are reported. Spectral analyses were carried out on the basis
Externí odkaz:
http://arxiv.org/abs/1408.1205
High-resolution optical spectra of the R Coronae Borealis (RCB) star V532 Oph at light maximum are discussed. The absolute visual magnitude M_V of the star is found to be -4.9 \pm 0.5. The elemental abundances suggest the star belongs to the majority
Externí odkaz:
http://arxiv.org/abs/1407.3696
The high resolution optical spectra of H-deficient stars, R Coronae Borealis stars and H-deficient carbon stars are analyzed by synthesizing the C2 Swan bands (0,1), (0,0), and (1,0) using our detailed line-list and Uppsala model atmosphere, to deter
Externí odkaz:
http://arxiv.org/abs/1211.6219