Comments:
1. HV 6998 was discovered by Swope (1936) and found, upon our request, by
the late Dr. M.Hazen in Harvard Observatory's logbooks. No finding chart
was avaible for this variable before. MinII = 13m.9 (V). J–K = 0.41.
2. M–m = 0.42 P. J–K = 0.39.
3. M–m = 0.28 P. J–K = 0.25.
ASAS-3 data were used to improve our results.
4. HV 7833 was discovered by Shapley and Boyd (1937) and found, upon our
request, by the late Dr. M.Hazen in Harvard Observatory's logbooks.
No finding chart was avaible for this variable before.
M–m = 0.43 P. J–K = 0.31.
5. MinII = 13m.25: (V), D = 0.06 P. Eccentric system: MinII–MinI
= 0.56 P.
J–K = 0.31.
6. J–K = 0.24.
7. MinII = 12m.9 (V). J–K = 0.50.
8. MinII = 12m.25 (V), D = 0.06 P. Eccentric system: MinII–MinI
= 0.59 P.
J–K = 0.31.
VSX gives a close period value, 3.68267 d,
and the same EA type for the star.
9. MinII = 15m.63: (CV). J–K = 0.43.
10. M–m = 0.22 P. J–K = 0.38.
11. MinII = 14m.43 (CV). J–K = 0.69.
12. J = 16m.55, H = 17m.46, K = 16m.92.
13. M–m = 0.17 P. J–K = 0.40.
14. MinII = 12m.80 (V), D = 0.15 P. J–K = 0.25.
15. M–m = 0.11 P. J–K = 0.36.
16. M–m = 0.22 P. J–K = 0.24.
17. Blue star. J = 16m.73, H = 16m.30, K = 15m.79.
ASAS-3 data were used to improve our results.
18. M–m = 0.22 P. J–K = 0.28.
19. M–m = 0.18 P. J–K = 0.33.
Remarks:
We present improved coordinates, types and light elements for 19 poorly studied
variables from the NSV catalog (Samus et al. 2007–2012).
The study was carried out using the publicly available electronic
archives of CCD observations of the ASAS-3 project (Pojmanski 2002), and
to the US Naval Observatory Image and Catalog Archive.
The new possibilities of
applying the online publicly available photometry from
Catalina Sky Survey (2013, data
release 2) allowed us to investigate and classify stars of interest.
Acknowledgments: The study is supported by a grant from the Program
"Origin and Evolution of Stars and Galaxies" of the Presidium of Russian
Academy of Sciences and by Russian Foundation for Basic Research grant
13‑02‑00664.
References:
Pojmanski, G., 2002, Acta Astron., 52, 397
Samus, N.N., Durlevich, O.V., Kazarovets, E V., Kireeva, N.N., Pastukhova E.N.,
et
al., 2007–2012,
General Catalogue of Variable Stars, Centre de Données Astronomiques de
Strasbourg,
B/gcvs
Shapley, H., Boyd, C.D., 1937, Harvard Observ. Ann., 105, 244
Swope, H.H., 1936, Harvard Observ. Ann., 90, No. 7, 207