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