NEW Cool Algols using the NSVS and 2MASS Databases

Cool algols have been defined as semi-detached eclipsing systems in which both stars are late-type G or K subgiants and one star has filled its Roche lobe (Popper 1980). They have very distinct light curves with wide eclipses and large curvature outside of eclipse because one star fills its Roche lobe. The periods are usually longer than two days.

Combination of the Northern Sky Variability Survey(NSVS; Wozniak et al., 2004) and the Two Micron All Sky Survey(2MASS; Strutskie et al. 2006) allows for the search of cool algol systems. Using the light curves provided by the NSVS and the color indices provided by 2MASS we have searched for cool systems with periods over two days having the correct light curve. Using Eclipsing Light Curve (ELC; Orosz 2000), we have modeled each system to find whether one star has filled its Roche lobe, indicating a cool algol.

Below is a table with the 10 new cool algols we have found. Linked to each star name is the NSVS page on that star. Also given is a light curve and model for each star. Please note that the epochs are not derived from one time of minimum, but are rather from the aggregate phased light curve. The periods are from the shape of this and not from several times of minimum. Therefore, predictions at times of minimum at many epochs later than the original observations should be viewed with caution.

NSVS10081872 is UZ Cnc and has already been classified as a possible cool algol (Popper 1996).

NSVS05168710 is YY Boo, previously classified as a F9IV star in the SIMBAD database, but not known as a cool algol.

We hope that you find this site useful. Thanks!

Nicole Kelley: nicole_kelley [at] berkeley.edu University of California, Berkeley Summer REU Intern at UGA

J. Scott Shaw: jss [at] physast.uga.edu University of Georgia Department of Physics and Astronomy

ELC model of NSVS08044036

Link to paper on Research

Link to cool algol ELC solutions

Star Name	LC	Model	RA (2000)	DEC (2000)	Magnitude	Points	Epoch	Period	2MASS ID	Cross ID
NSVS****	link	link	deg	deg			HJD 2451000+	days
01667524	LC	M	10.880430	+62.665520	12.773	171	335.355	2.19879	00433123+6239557
01690749	LC	M	19.793240	+62.396801	10.281	129	335.355	11.72311	01191033+6223483
04239237	LC	M	60.628170	+52.855179	10.563	62	401.310	5.56985	04023070+5251179
05168710	LC	M	233.867813	+43.480000	11.994	231	274.212	3.93198	15352831+4328491	V*YY Boo
05873479	LC	M	312.959106	+43.323719	12.741	265	281.396	8.22854	20515020+4319298
06983718	LC	M	85.042961	+35.459980	12.836	254	275.191	4.41302	05401031+3527360
08044036	LC	M	263.61252	+32.225281	11.952	244	274.391	3.50150	17342709+3213312	NSV 9188
10054338	LC	M	122.43419	+8.546180	12.860	49	491.433	2.71960	08094425+0832462
10081872	LC	M	120.847420	+19.181761	10.814	119	274.241	11.58194	08032340+1910545	V* UZ Cnc
14139046	LC	M	293.81281	-1.909620	13.043	129	274.435	8.55989	19351502-0154356

Acknowledgements: Thank you to M. Wood at Florida Institute for Technology and J. Coughlin at Emory University. This work has been funded by a partnership between the National Science Foundation (NSF AST-0552798) Research Experiences for Undergraduates (REU) and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Aeronautics and Space Administration and the National Science Foundation.  We also thank Northern Sky Variability Survey (NSVS) and the University of California, operator of the Los Alamos National Laboratory under Contract No. W-7405-ENG-36 with the US Department of Energy.

References:

Orosz, J.A., and Hauschildt, P.H. 2000, A&A, 364, 265

Popper, D.M. 1980, AJ, 96, 1040

Popper, D.M. 1996, ApJS, 106, 133

Skrutskie, M.F. et al. 2006, AJ, 131, 1163, The Two Micron All Sky Survey (2MASS): Public Data Release

Wozniak, P.R., et al., 2004, AJ, 127, 2436, Northern Sky Variability Survey: Public Data Release