Optical observations of a BL Lacertae outburst in B and V Filters

[nikola.antonov]

Following the outburst information of BL Lac announced by ATel #16806, I performed photometric observations in B and V bands with the 0.25-m F/4.8 Newtonian reflector at Meshtitsa Observatory, Sofia, Bulgaria.

The observations on September 11, show a brightness rise to 12.8 in V.

Time	Mag	Mag. Err.	Filter
2460565.32733	12.820	0.002	V
2460565.33453	12.811	0.003	V
2460565.33737	12.807	0.003	V
2460565.34471	12.811	0.003	V
2460565.34756	12.815	0.003	V
2460565.35042	12.808	0.003	V
2460565.35326	12.828	0.003	V
2460565.35611	12.842	0.003	V
2460565.35897	12.813	0.003	V
2460565.36182	12.788	0.003	V
2460565.36466	12.754	0.003	V
2460565.36752	12.751	0.003	V
2460565.37037	12.730	0.003	V
2460565.37323	12.760	0.003	V
2460565.32381	13.632	0.003	B
2460565.33154	13.611	0.005	B
2460565.33309	13.606	0.005	B
2460565.33595	13.609	0.005	B
2460565.34329	13.620	0.005	B
2460565.34613	13.572	0.005	B
2460565.34898	13.641	0.005	B
2460565.35184	13.632	0.005	B
2460565.35469	13.587	0.005	B
2460565.35755	13.594	0.005	B
2460565.36039	13.579	0.005	B
2460565.36324	13.564	0.005	B
2460565.36610	13.595	0.005	B
2460565.36895	13.537	0.005	B
2460565.37181	13.561	0.005	B

I am also attaching a light curve from my observations over the last 2 months (Jul - Sep 2024).

The telescope is part of a remotely operated observatory equipped with Bessel BVR photometric filters and an ASI533MM Pro CMOS camera. An exposure of 120 sec at SNR > 250 was used.

[1eboeneker]

Awesome, @nikola.antonov! I see that BL Lac has shown a slight increase in mean magnitude in the past few years, at least that is what I see in data at the AID:

Thanks for sharing!

[nikola.antonov]

Thanks, Enrique,

It seems that the outburst is over.

[nikola.antonov]

The BL Lac outburst seems to be continuing. Today, its apparent magnitude has risen again to 12.755 V (+/- 0.004), after only 4 days ago it was down to 13.222 V (+/- 0.006)!