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Be star

Alert Notice 602: CE Tau Observations Requested to Supplement BRITE-Constellation

October 17, 2017BRITE-Constellation (, a network of nano-satellites, is currently taking photometric observations of  the Taurus field (full target list and field specifications given  Within this field is CE Tau, a red supergiant with significant (0.5 mag) variations over timescales of months. Dr.

Alert Notice 562: Photometry of V725 Tau needed immediately

November 15, 2016: Dr. Franco Giovannelli (Istituto di Astrofisica e Planetologia Spaziali di Roma) has requested AAVSO assistance in monitoring V725 Tau, the Be star in the high-mass X-ray transient A0535+26/HDE245770, in order to plan for the X-ray outburst that follows 8 days after the optical brightening that occurs at periastron passage.

Periastron passage will occur on 16 November 2016, so coverage is needed beginning immediately and continuing for at least 15 days after periastron, until December 2.

Alert Notice 559: Observations of CI Cam needed to support spectroscopy

October 19, 2016: Kelly Gourdji and Marcella Wijngaarden (graduate students at the University of Amsterdam/Anton Pannekoek Institute for Astronomy) have requested AAVSO observers' assistance in providing optical photometry of CI Cam in support of their high-resolution spectroscopy with the Mercator telescope + Hermes spectrograph in La Palma from now through January 2017.

Alert Notice 555: Correction to Alert Notice 554 on V420 Aur (HD 34921)

October 4, 2016: In AAVSO Alert Notice 554 the star was inadvertently referred to as V420 Oph in the sections creating charts and reporting observations.

Charts with a comparison star sequence for V420 Aur may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name V420 AUR.

Coordinates for V420 Aur (2000.0): R.A. 05 22 35.23  Dec. +37 40 33.6

Alert Notice 554: Observations of V420 Aur (HD 34921) needed to support spectroscopy

Note added October 4, 2016: In the original version of this Alert Notice, V420 Aur was referred to as V420 Oph in the sections on creating charts and reporting observations. Also, the range was given as V=7.15-7.35  when the correct value is V=7.35-7.51. The text below has been corrected. Apologies to the PI's for the error.

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