COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 2283 Konkoly Observatory Budapest 1983 February 23 HU ISSN 0374-0676 SPECTROPHOTOMETRIC OBSERVATIONS OF NOVA SAGITTARII 1982 NEAR MAXIMUM LIGHT Spectrophotometric observations of Nova Sgr 1982, when it was near maximum light, have been obtained with the McGraw-Hill Observatory 1.3 meter telescope. These data were taken on both 1982 October 13 (1h48m and 2h02m UT) and 1982 October 14 (1h35m UT) using the intensified reticon scanner. The night sky was subtracted and the fluxes were calibrated using observations of the white dwarf EG 139 taken on the same night. Spectral features have been measured and identified using the single observation from the second night. This spectral scan is shown in Figure 1. [FIGURE 1] The spectrum of Nova Sgr 1982 taken on October 14, 1982. The peak of the Hbeta line is at approximately 3.6 x 10^-12 ergs cm^-2 s^-1 angstrom^-1, but has been truncated on this plot. The original resolution was ~3 angstrom, and the plot has been smoothed to ~5 angstrom. Prominent features can be identified from Table I. A plot of the magnitudes given in the IAU Circulars by Kosai and Honda (1982), Mack and Cousins (1982), Churms and Hers (1982), and Elias and Verdenet (1982) shows Nova Sgr 1982 exhibited a double maximum similar to those seen in DM Gem (Campbell 1915) and NQ Vul (Cottrell and Smith 1978). We estimate from looking at the light curve that our observations were made within +/-1 day of the first and brighter maximum when the star was near eighth magnitude. Judging from the strength of the emission lines it seems likely that our observations are taken just after maximum light, which probably occurred on ~12 October 1982. Thus the first observations at approximately ninth magnitude by Kosai and Honda may have caught the nova during a pre-maximum halt. The spectrum was observed from ~3700 angstrom to ~5400 angstrom, although the wavelengths are only properly calibrated between ~3900 angstrom and ~5100 angstrom. The Balmer series of H are seen in emission with weak, violet displaced absorption. Other prominent emissions include Fe II, Ti II, and Ca II. No satisfactory identification was found for several lines and blends. Table I lists the measured lines together with their velocities, corrected to the sun. The mean H emission velocity is found to be +69 +/- 25 km s^-1 (Hbeta - Hepsilon). The mean from the emissions of the ionized metals is +26 +/- 29 km s^-1, but blending of these lines causes some uncertainty in this value. The mean absorption velocity from seven lines is -619 +/- 27 km^-s , thus indicating a net outward flow of ~700 km s^-1. All of the absorption lines are weak, shallow, and single. The weakness of the absorptions and the presence of only low excitation emission lines reinforces the suggestion that the nova was observed at a very early post-maximum phase (McLaughlin 1960). Small differences in the spectra between the two nights are present. The Balmer lines show a small central absorption in the peak of the emission on the first night which is not present on the second night, and in general Table I Measured Features in Nova Sgr 1982 Radial Velocities Ion (multiplet) lambda0(angstrom) (km s^-1) Comments Emission Absorption H 10 3797.90 * * H 9 3835.39 * * Fe II (127) ? ~3864 * H 8 3889.05 * * Ti II (34) 3900.55 -29 Ti II (34) 3913.46 +50 Ca II-K 3933.66 +216 -491 Hepsilon 3970.07 +124 -609 Blend with Ca II-H Fe II (127) ? ~4024 Fe II (126) ? ~4032 Unidentified ~4035 Ti II (87) 4053.81 -40 Hdelta 4101.74 +72 +730 Fe II (22) 4124.79 +86 Fe II (27) 4128.74 (-66) Blend with Si II 4128(3) Fe II (27) 4173.45 +163 Fe II (28) 4178.86 -37 Fe II (27) 4233.17 +3 Ti II (41) 4300.05 (+46) Blend with TiII4301(41)? Unidentified ~4318 Hgamma 4340.47 +3 -617 Fe II (27) 4351.76 -120 Ti II (51) 4399.77 -148 Fe II (27) 4416.82 +163 Blend with Fe TI 4414(32)? Unidentified ~4448 Ti II (31) 4468.49 -80 Fe II (37) ~4490 Blend Fe II (37), (38) ~4520 Blend Ti II (50), Fe II (37) ~4534 Blend Fe II (37), Cr II (44) ~4556 Blend Fe II (37),(38) ~4588 Blend Hbeta 4861.33 +79 -653 Fe II (42) 4923.92 +85 -589 Fe II (42) 5018.43 +57 -645 Fe II (42) 5169.03 * * Fe II (49) 5197.57 * Si II ? ~5202 * Fe II (49) 5234.62 * Fe II (49) 5275.99 * Fe II (49),(48) 5316.61 * Blend * Outside the region of well-established wavelengths ( ) Velocity uncertain due to line blending the emission lines appear to be about 30% stronger on the second night, further supporting the suggestion that the first observation was obtained very near maximum light. We thank Dr. Matt Johns for his help with the instrument during our observing run. J. R. SOWELL and A. P. COWLEY Astronomy Department University of Michigan Ann Arbor, Michigan 48109 U.S.A. References: Campbell, L. 1915, Harvard Ann., 76, No. 11. Churms, J. and Hers, J. 1982, IAU Cir. 3736. [BIBCODE 1982IAUC.3736....1D ] Cottrell, M. J. and Smith, S. E. 1978, Pub. Astro. Soc. Pac., 90, 615. [BIBCODE 1978PASP...90..615C ] Elias, D. P. and Verdenet, M. 1982, IAU Cir. 3747. [BIBCODE 1982IAUC.3747....2E ] Kosai, H. and Honda, M. 1982, IAU Cir. 3733. [BIBCODE 1982IAUC.3733....1K ] Mack, P. and Cousins, A. W. J. 1982, IAU Cir. 3733. [BIBCODE 1982IAUC.3733....1K ] McLaughlin, U. B. 1960, "The Spectra of Novae", in Stellar Atmospheres, ed. J. L. Greenstein, (The University of Chicago Press; Chicago), p. 585. [BIBCODE 1960stat.conf..585M ]