HM Sagittae

A. A. Boyarchuk, Crimean Astrophysical Observatory, cables that observations by Belyakina, Noskova and Saveleva show that HM Sge increased rapidly in brightness from V = 11.49 on July 14 to V = 11.04 on July 20. The corresponding changes in color were from B-V = +0.72, U-B = -0.62 to B-V = +0.33, U-B = -0.43. C. W. McCracken, Goddard Space Flight Center, reports that an image-tube spectrogram (range 4650-7350 A, dispersion 82 A/mm) was obtained on July 23.20 UT by L. W. Brown, R. W. Hobbs and himself with the 91-cm reflector. W. A. Feibelman has identified about 40 emission lines that show that the spectrum is typically that of a planetary nebula. Lines of H-alpha, H-beta, He I, He II, Si II, [N II], [O I], [O II], [O III], [S III], [A III] and [A IV] are superposed on a stellar continuum. Weak lines of [Fe III], [Fe VI], [Cl III] and [P II] are present, in addition to several unidentified lines observed in NGC 7027 and other high-excitation planetaries.