37 citations · 117 across the 13 of their papers we have counts for
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Photospheric Helium Abundance in Cool Giants -- A Comprehensive Study
B. P. Hema, Gajendra Pandey
High-resolution optical spectra of sixteen red giants, two early asymptotic giant branch (AGB) stars, and two supergiants, having no/minimal to super lithium (Li)-rich abundances,…
Helium Abundance of the Sun: A Spectroscopic Analysis
Satyajeet Moharana, B. P. Hema, Gajendra Pandey
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 rema…
Measuring Hydrogen-to-Helium Ratio in Cool Stars
B. P. Hema, Gajendra Pandey
Conventionally, the helium-to-hydrogen ratio for the stars are adopted to be 0.1, as standard, unless, the stars are severely deficient in hydrogen like in RCB-class, or the stars'…
Revised surface abundances of R Coronae Borealis stars
Gajendra Pandey, B. P. Hema, Arumalla B. S. Reddy +5
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…
Investigation of the Helium Enhancement in a Super Lithium Rich Giant HD 77361
B. P. Hema, Gajendra Pandey
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 deta…
Helium Enhancement in the Metal Rich Red Giants of Omega Centauri
B. P. Hema, Gajendra Pandey, R. L. Kurucz +1
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 c…
High resolution spectroscopy of the relatively hydrogen-poor metal rich giants in the globular cluster Omega Centauri
B. P. Hema, Gajendra Pandey, R. Srianand
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 com…
Abundance analyses of the new R Coronae Borealis stars: ASAS-RCB-8 and ASAS-RCB-10
B. P. Hema, Gajendra Pandey, Devika Kamath +3
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.…
The hot Gamma-Doradus and Maia stars
L. A. Balona, C. A. Engelbrecht, Yogesh C. Joshi +8
The hot ~Doradus stars have multiple low frequencies characteristic of ~Dor or SPB variables, but are located between the red edge of the SPB and the blue edge of the ~Dor…
Discovery of relatively hydrogen-poor giants in the Galactic globular cluster Omega Centauri
B. P. Hema, Gajendra Pandey
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 Om…
High-resolution optical spectroscopy of the R Coronae Borealis star V532 Ophiuchi at maximum light
N. Kameswara Rao, David L. Lambert, Vincent M. Woolf +1
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…
The Galactic R Coronae Borealis Stars and the Final He-shell Flash Object V4334 Sgr (Sakurai's Object): A Comparison
B. P. Hema, Gajendra Pandey, David L. Lambert
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,…
The Galactic R Coronae Borealis stars : the C2 Swan bands, the carbon problem, and the 12C/13C ratio
B. P. Hema, Gajendra Pandey, David L. Lambert
Observed spectra of R Coronae Borealis (RCB) and hydrogen-deficient carbon (HdC) stars are analyzed by synthesizing the C2 Swan bands (1,0), (0,0), and (0,1) using our detailed lin…