by Anthony Ayiomamitis
The large-amplitude short-period pulsating star XX Cyg is a fast pulsating variable star with a period of 194.2 minutes and which involves a delta mag of 0.85 (V) magnitudes during this brief time interval. XX Cygni was discovered in 1904 by Mme. Lydie Ceraski and has been studied fairly intensely with indications suggesting of a slight increase in its period over time. Further details from the General Variable Star Search Gateway are available
here whereas an AAVSO finder chart is available
here.
Technical Details:
Date: Aug 28-29, 2010 @ 21:50 - 05:37 UT+3
Location: Athens, Greece (38.2997° N, 23.7430° E)
Equipment: AP 160 f/7.5 StarFire EDF, AP 1200GTO GEM, SBIG ST-10XME, SBIG CFW10, SBIG LRGB filters
Integrations: Lum @ 345x75 sec, 2x2 binning, 2.34"/pixel, -10.0d C
Further details are available here.