36 citations · 103 across the 22 of their papers we have counts for
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Age determinations of the open star clusters King 14 and NGC 146
Valentin Kopchev, Petko Nedialkov, Georgy Petrov
We based on 2MASS J and Ks photometry for the open star clusters King 14 and NGC 146, and using color magnitude diagrams with isochrones fit we have found an age of log(age) = 7.8…
Age determination of possible binary open clusters NGC 2383/NGC 2384 and Pismis 6/Pismis 8
Valentin Kopchev, Petko Nedialkov, Georgy Petrov
Based on 2MASS J and Ks photometry for the open star clusters NGC 2383, NGC 2384,Pismis 6, Pismis 8 and using color magnitude diagrams with isochrones fit, we found an age of $\log…
Optical monitoring of the z=4.40 quasar Q 2203+292
E. P. Ovcharov, P. L. Nedialkov, A. T. Valcheva +5
We report Cousins R-band monitoring of the high-redshift (z=4.40) radio quiet quasar Q 2203+292 from May 1999 to October 2007. The quasar shows maximum peak-to-peak light curve amp…
Calibrated Tully-Fisher relations for edge-on galaxies in the BVRI system
O. Stanchev, P. Nedialkov, Ts. Georgiev
Calibrated Tully-Fisher relations ''absolute magnitude - HI line width'' for spiral galaxies oriented edge-on are derived from published data. The slope of the linear fits, especia…
First optical identification of a suprsoft X-ray source in M31
P. Nedialkov, M. Orio, K. Birkle +5
We propose the first association of an optical counterpart with a luminous supersoft X-ray source in M31, RX J0044.0+4118, observed with ROSAT in July 1991. The PSPC position is at…
Optical identification of supersoft X-ray sources in M31
Marina orio, Roberto Casalegno, Chris Conselice +3
We report on initial progress in a program of optical identification of supersoft X-ray sources in M31, pursued mainly with the WIYN telescope. We propose the identification of one…