B. Hidayat, M. Ikbal Arifyanto, J. Aria Utama, and S. Athiya, Bosscha Observatory, Lembang, write: "Spectroscopic observations of N Vel 1999 were obtained at the Bosscha Schmidt telescope (+ objective prism; dispersion 31.5 nm/mm at H-gamma) on June 1.50 and 2.50 UT, with unfiltered IIa-O plates exposed for 12 and 6 min, respectively. Although the 12-min exposure yielded an overexposed spectrum, emission lines of H, He, and [O III] are clearly distinguishable. Based on the three spectra collected on June 2, the following lines are seen (positions and widths of the lines are based on a standard spectrum of a B9 star, secured with the same telescope): [O III] 500.7-nm (half the strength of H-beta), 495.9- nm (half the strength of H-beta), 436.3-nm (certainly observable); [Fe II] 492.4-nm (rather faint but traceable), 423.3-nm (faint); S II(?) 406.8-nm (rather broad, confuse, barely visible); [Ne III] 386.9-nm (half the strength of H-beta). All of the H lines down to H_7 appear on our plates; their estimated width is about 20.0 nm, decreasing rather slowly toward H_7. Shallow depression on the blue side of H-beta is noticable. He II 468.6-nm is rather wide."
International Astronomical Union Circular
- Pub Date:
- June 1999