Photometric and spectroscopic observations of the outburst of the symbiotic star AG Draconis between March and June 2016

David Boyd, Variable Star Section, British Astronomical Association, []


The symbiotic star AG Dra experienced a double-peaked outburst of 0.6 magnitudes in April and May 2016. Photometry and spectroscopy through the outburst showed the B-V colour index varying linearly with the

V magnitude and enabled the temperature variation of the hot star to be calculated from the changing flux in the Hβ and He II 4686Å emission lines.


2016, Dezember 24, Ernst Pollmann

The Eruptive Stars Information Letter 2016-08

International Observing Campaign "Photometry and Spectroscopy of P Cygni"

E. Pollmann and Th. Bauer, JAAVSO Volume 40, 2012

2016, Februar 11, Ernst Pollmann

The Long-Term Binary System VV Cep

Anlässlich des bevorstehenden Bedeckungsereignisses im Doppelsternsystem VV Cephei in den Jahren 2017-19, ist vom Unterzeichner, sowie von Philip Bennet & Jeff Hopkins bei IBVS unter der Nr. 6156 eine, unter amateur-spektroskopischen Gesichtspunkten verfasste Arbeit, veröffentlicht worden. Siehe hierzu:

2016, Februar 11, Ernst Pollmann

Monitoring the radial velocity of HeI 6678 of gamma Cas

Spektren der Datenbank BeSS, von Beobachtern der internationalen ARAS-Gruppe, ermöglichten die Ausarbeitung der o. g. IBVS-Veröffentlichung. Siehe:

2016, Juni 06, Ernst Pollmann

Long-term radial velocity of the HeI 6678 line of zeta Tau

Attempts to detect long-term cyclic RV variations of the HeI6678 absorption line in the spectrum of ζ Tau (Stefl et al. (2007) found quasi-period = 1503 d; Ruzdjak et al. (2009) found quasi-period = 1325 d (± 67); we found quasi-period = 1190 d (± 35)) points out that the long-term RV period at least since 1993 has constantly decreased.
2016, Juli 02, Ernst Pollmann

Variability of the HeI 6678 Emission in delta Sco
δ Scorpii (HD143275, HR5953) is a 2.3 magnitudes bright and 1976 by McAllister (1978) interferrometrically discovered Be binary star. During each periastron (period = 10.8 years) some ring material may flow from the primary ́s Roche lobe into the secondary ́s Roche lobe. Du ring that process the disk becomes denser and single-, double- or triple peak profiles may be observable.
Following the generally accepted assumption that the disk of this binary system is being fed due to outbursts of matter ejected from the stellar surface (Miroshnichenko et al., 2003), and since the He I 6678 line forms near the photosphere of the primary component one can expect a correlation between the equivalent width of the Halpha and and He I 6678 lines.
This study of a correlation between Hα- and He I 6678 equivalent width (EW) and the behavior of the He I 6678 line profiles have been performed by the author at the observatory of the “Vereinigung der Sternfreunde Köln” (Germany) with a 40 cm Schmidt-Cassegrain-telescope C14, the slit-grating-spectrograph LHIRES III with a spectral resolving power R ~ 17000 and a CCD-camera (768 x 512 pixel, pixel size 9μ.
2016, August 25, Ernst Pollmann