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ATEL # 1858; H. Bond (STScI)
on 30 Nov 2008; 23:42 UT
Distributed as an Instant Email Notice (Transients)
Password Certification: Howard E. Bond (email@example.com)
Subjects: Optical, Request for Observations, Binaries, Transients, Variables, Stars
The hydrogen-deficient central star of the planetary nebula Longmore 4 (Lo 4; J2000: 10 05 45.7 -44 21 32) normally has a PG 1159-type absorption spectrum, with the O VI 3811-3834 doublet in emission. On three past occasions (one in 1992, two in 2006; H.E. Bond, 2008, ASP Conf Series 391, p. 129) the spectrum has changed temporarily to an emission-line [WCE] type, with strong emission at the C IV+He II complex near 4659-4686 A and O VI 5291. A spectrum obtained on 2008 Nov 30.27 with the SMARTS 1.5m telescope at Cerro Tololo by M. Hernandez and F. Walter shows that a new emission-line outburst is underway. Spectroscopic and photometric monitoring, including high-speed photometry of the star's GW Vir-type pulsations, is desirable throughout the duration of the current event.