A slitless spectrograph for small telescopes: initial results

1Zhilyaev, BE, 2Sergeev, AV, 2Andreev, MV, 2Godunova, VG, 1Reshetnyk, VM, 2Taradiy, VK
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2International Center for Astronomical, Medical and Ecological Research of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2013, 29(3):64-0
Start Page: Instruments and Devices
Language: Russian

A slitless UBVR spectrograph is built for use with small telescopes. Some results of test observations with the Zeiss-600 telescope on peak Terskol give grounds to expect that the spectrograph is an effective tool for the study of transients in variable stars with high temporal resolution. The resolution of the spectrograph is R ≈ 100 in the vicinity of 480 nm and the accuracy of the wavelength determination is about 3 nm. The spectrograph provides a moderate signal-to-noise ratio for stars up to 16th magnitude. It allows us to measure the equivalent widths of not blended lines down to about 0.1 nm. Specialized software based on the theory of quantum statistics is developed. It allows one to detect variations about 10-5—10-6 in the relative power spectrum with respect to the bolometric flux from a star. Some observations obtained with the spectrograph revealed variations in the Balmer emission lines and lines of Ca II H, K in the flare star EV Lac in the subsecond range. Spectroscopic monitoring allows us to investigate stellar flares with small amplitudes, to perform a compre hensive colorimetric analysis of the burst plasma, to determine flare temperature and sizes at a maximum of light intensity. Observations of a transit of HAT-P- 1 B showed that the chromospheric activity index of the hosting star remains constant during a transit. A slitless low-resolution spectrograph opens new prospects for the study of active processes on stellar surfaces.

Keywords: small telescope, spectrograph

1.V. I. Pronik and L. M. Sharipova, USSR Inventor’s Certificate No. 1822932, Byull. Izobret., No. 23 (1993).

2.V. V. Busarev, V. V. Prokof’eva-Mikhailovskaya, and A. N. Rublevskii, “Development and application of the spectrum-frequency method for studying surfaces of atmosphereless bodies,” Izv. Krym. Astrofiz. Observatorii 105(6), 95–102 (2009).

3.B. E. Zhilyaev, K. O. Stetsenko, A. V. Sergeev, et al., “Low-resolution spectrophotometer for rapid spectrometry and photometry of stars,” Kinematika i Fizika Nebes. Tel. Appendix, (6), 422–425 (2010).

4.I. Yu. Alekseev, E. A. Baranovskij, R. E. Gershberg, et al., “Modeling of emission spectra and the flaring red dwarf EV Lac: Active regions, flares, and microflares,” Astron. Rep. 47, 312–325 (2003).

5.I. Yu. Alekseev and O. V. Kozlova, “Starspots and active regions on the chromospherically active binary MS Ser,” Astron. Astrophys. 403, 205–215 (2003).

6.G. A. Bakos, R. W. Noyes, G. Kovacs, et al., “HAT-P-1b: a large-radius, low-density exoplanet transiting one member of a stellar binary,” arXiv:astro-ph/0609369v2 15 Sep 2006.

7.B. W. Bopp, “Spectroscopic studies of flare stars: EV Lac, EQ Peg, AD Leo, and V1054 Oph,” Mon. Not. R. Astron. Soc. 168, 255–261 (1974).

8.W. Freudling, M. Kummel, J. Haase, et al., “The Hubble legacy archive NICMOS grism data,” Astron. Astrophys. 490, 1165–1179 (2008).

9.G. H. Herbig, “Emission-line stars associated with the nebulous cluster NGC 2264,” Astrophys. J. 119, 483–495 (1954).

10.A. A. Hoag and D. J. Schroeder, ““Nonobjective” grating spectroscopy,” Publ. Astron. Soc. Pac. 82, 1141–1145 (1970).

11.H. A. Knutson, A. W. Howard, and H. Isaacson, “A correlation between stellar activity and hot Jupiter emission spectra,” arXiv:1004.2702v2 [astro-ph.EP] 22 Jul 2010.

12.P. Massey and C. B. Foltz, “The spectrum of the night sky over Mount Hopkins and Kitt Peak: Changes after a decade,” Publ. Astron. Soc. Pac. 112, 566–573 (2000).

13.D. Montes, M. J. Fernandes-Figueroa, E. D. Castro, et al., “Excess Hα emission in chromospherically active binaries: the spectroscopic survey,” Astron. Astrophys., Suppl. Ser. 109, 135–145 (1995).

14.D. Montes, M. J. Fernandes-Figueroa, M. Cornide, et al., “The behaviour of the excess Ca II H and K and Hɛ emissions in chromospherically active binaries,” Astron. Astrophys. 312, 221–233 (1996).

15.E. N. Parker, “Nanoflares and the solar X-ray corona,” Astrophys. J. 330, 474–479 (1988).

16.P. W. A. Roming, T. E. Kennedy, K. O. Mason, et al., “The Swift ultra-violet/optical telescope,” arXiv:astroph/0507413.

17.Y.-K. Sheen and Y.-I. Byun, “The night sky spectrum of Mount Bohyun,” J. Korean Astron. Soc. 37(2), 87–90 (2004).

18.O. Thizy, C. Buil, C. Francois, and C. Neiner, “Organizing a professional-amateur collaboration with a Lhires III spectrograph,” Planet. Space Sci. 56, 1878–1881 (2008).

19.O. C. Wilson, “Spectrographic observations of a flare star,” Publ. Astron. Soc. Pac. 73, 15–19 (1961).

20.B. E. Zhilyaev, Ya. O. Romanyuk, O. A. Svyatogorov, et al., “Fast colorimetry of the flare star EV Lacertae from UBVRI observations in 2004,” Astron. Astrophys. 465, 235–240 (2007).

21.B. E. Zhilyaev and I. A. Verlyuk, in Flares and Flashes, Ed. by J. Greiner, H. W. Duerbeck, and R. E. Gershberg (Springer-Verlag, Berlin, 1994), pp. 82–84.