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AAVSO Special Notice #152: Increased activity in the symbiotic star AX Persei AAVSO HOME > publications > special notice

AAVSO Special Notice #152

Increased activity in the symbiotic star AX Persei
April 6, 2009

U. Munari et al (CBET #1757, D.W.E. Green, editor) notes that the
symbiotic star AX Per has brightened significantly and become bluer in
color between 2009 February 28 and 2009 April 1.  The star has increased
from B=12.56 to B=11.55, and changed from (B-V) = +1.08 to +0.82.  This
is the brightest AX Per has been since the outburst of 1988-1992. 
Spectrophotometry of the star shows the presence of bright,
high-ionization lines.  Overall, the spectrum indicates the central
engine of the symbiotic star has "switched on", increasing in both
luminosity and temperature.  This activity may be a precursor to a major
outburst; Munari et al indicate AX Per exhibited similar behavior about
one year prior to the 1988-1992 outburst.

Increased monitoring of AX Per is encouraged, both visually and with
filtered photometry.  Observers with multiple filters are encouraged to
transform their data to a standard system, to enable to calibration of
all magnitudes and colors.  Intensive time-series observations are not
critical at this time, but may be requested in the future.  Please
obtain the highest signal-to-noise data feasible (S/N 50 or higher).

AX Persei is located at the following (J2000) coordinates:

RA: 01 36 22.70 , Dec +54 15 2.0

Charts for AX Persei may be plotted using AAVSO VSP:

Please submit all data to the AAVSO using the name "AX PER" 
(AUID 000-BBD-098).

This AAVSO Special Notice was prepared by M. Templeton.


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