The Virtual Telescope - Bellatrix Astronomical Observatory


	EG Aqr: a new SU UMa CV EG Aqr, imaged on Nov. 8, 2006. The International Astronomical Union published CBET 736 with the following findings! On Nov. 8.44, 2006 R. Stubbing (AU) spotted this star at mag. 12.4, that is clearly in a bright outburst. The historical record shows that only two previous outbursts were detected in past: in 1958 and 1959. So, this new one was the very first after such a long time, ready to be investigated with modern technology. As soon as the evening reached Italy, the Virtual Telescope was remotely slewed to this very-high-priority target, which appeared still bright. Time-resolved photometry was promptly started and real-time data reduction performed: after about 30 minutes, it was clear that EG Aqr was clearly showing superhumps (0.10 mag large), a clear signature of SU UMa stars in superoutburst. So, the Virtual Telescope observations discovered the nature of this cataclysmic variable. A quick period determination provided a preliminary candidate of 115 minutes, close to the lower limit of the CV period gap. During the run, the star faded of about 0.15 mag. The lighcurve is shown below. The following night, the Virtual Telescope observed the star again, finding it 0.3 mag brighter. The coverage was 4h long and data reduction showed beautiful superhumps, 0.35 mag. large. Period analysis provided a period of 1.99 hours, very close to period gap's lower limit. The lightcurve is posted below. On Nov. 10, 2006 I did a 5h-long run, under excellent sky conditions. The resulting lightcurve is below: Superhumps show a different profile, but same amplitude as the previous day. The star was only 0.05 mag. fainter. PDM period analysis provided a period candidate of 1.89 h, marginally shorther than on the previous night. I managed to phase both night data with the old (1.99h) period candidate, getting the following plot: The red dots (10 Nov.) are clearly not properly phased, while the black ones work fine. Finally, I joined the two nights to perform another period search: it resulted in 1.9044h: These data have been using in a professional paper in press (18 aug. 2007) Gianluca Masi The Virtual Telescope - 10 November 2006

EG Aqr: a new SU UMa CV

EG Aqr, imaged on Nov. 8, 2006.

The International Astronomical Union published CBET 736 with the following findings!

On Nov. 8.44, 2006 R. Stubbing (AU) spotted this star at mag. 12.4, that is clearly in a bright outburst. The historical record shows that only two previous outbursts were detected in past: in 1958 and 1959. So, this new one was the very first after such a long time, ready to be investigated with modern technology.

As soon as the evening reached Italy, the Virtual Telescope was remotely slewed to this very-high-priority target, which appeared still bright. Time-resolved photometry was promptly started and real-time data reduction performed: after about 30 minutes, it was clear that EG Aqr was clearly showing superhumps (0.10 mag large), a clear signature of SU UMa stars in superoutburst. So, the Virtual Telescope observations discovered the nature of this cataclysmic variable. A quick period determination provided a preliminary candidate of 115 minutes, close to the lower limit of the CV period gap. During the run, the star faded of about 0.15 mag. The lighcurve is shown below.

The following night, the Virtual Telescope observed the star again, finding it 0.3 mag brighter. The coverage was 4h long and data reduction showed beautiful superhumps, 0.35 mag. large. Period analysis provided a period of 1.99 hours, very close to period gap's lower limit. The lightcurve is posted below.

On Nov. 10, 2006 I did a 5h-long run, under excellent sky conditions. The resulting lightcurve is below:

Superhumps show a different profile, but same amplitude as the previous day. The star was only 0.05 mag. fainter. PDM period analysis provided a period candidate of 1.89 h, marginally shorther than on the previous night. I managed to phase both night data with the old (1.99h) period candidate, getting the following plot:

The red dots (10 Nov.) are clearly not properly phased, while the black ones work fine.

Finally, I joined the two nights to perform another period search: it resulted in 1.9044h:

These data have been using in a professional paper in press (18 aug. 2007)

Gianluca Masi

The Virtual Telescope - 10 November 2006