Lightcurve of the week 208

By: Dr. Franz-Josef (Josch) Hambsch, (VVS; BAV.; GEOS RR Lyr Group; AAVSO)

I am a retired nuclear physicist of German origin, but live in Belgium since 1984. My interest in astronomy started with a book of the constellations from the famous Kosmos Verlag in Germany when I was around 10 years old. It took, however, until the age of 18 when I bought my first telescope, an 11.5 cm (4.5 inch) f/8 Newtonian on a simple equatorial mount. I lived a few years in Frankfurt/Main and used it from the attic window to observe the Moon as not much more was visible from the city even several decades ago. When we moved to Darmstadt, I bought a second hand C8 around 1980 and used it visually from the balcony of our apartment. Then we moved to Belgium for my work and the telescope moved with me, though during several years my astronomical activity was on a very low level. Around 2000, when I bought a decent mount and build a roll-off-roof observatory, astronomical activities changed drastically. By then CCD’s had entered the amateur world already for some years and I decided to buy an SBIG ST8 CCD. The first years I was interested in getting pretty pictures. I joined an organization in Germany (International Amateur Observatory) which has built in the meantime several observatories in Namibia on Hakos farm. I went to Namibia several times between 2001 and 2012 to enjoy the incredible weather and darkness, and of course the Southern Sky. One of the images taken has been the Astronomy Picture of the day in 2006.

A change in my interests had taken place by then. In 2003, the Gamma Ray Burst GRB030329 occurred. I could follow it from my Belgian observatory over several days. This event excited me as a scientist. Besides deep-sky objects, I also started to observe variable stars. The latter took over with time and I am only doing variable star observations and follow-up now. During the past 15 years, I took first partnership with two American fellow amateurs in a telescope rental in New Mexico close to New Mexico skies. Unfortunately, weather conditions though better than in Belgium where not too good due to the so called “monsoon period” in Summer time, plenty of snow in the winter, as well as windy conditions during many clear nights. Since 2011, I have found the ultimate place to put a private observatory, namely the Atacama Desert in Chile. I have now passed the tenth year of remote observations from this place. It averages about 320 clear nights per year, has perfect internet connection and a very knowledgeable landlord, helping promptly in case of problems whatever kind. If I remember correctly, I am a member of the AAVSO since around 2009. I have participated in several AAVSO meetings since then. I have also submitted more than 4.8 million observations to the AAVSO database, which is due to the superb remote site in Chile. My activity in follow-up of variable stars has culminated in more than 130 refereed publications (and counting) in professional astronomical journals as co-author. One of these was in Nature (Marsh et al. 2016) and one in Science Advances (Damasso et al. 2020).

To HOYS, I came in July 2018 when I got to know Dirk Froebrich during a presentation he gave at the Joint BAA-AAVSO meeting on Variable stars at the University of Warwick, Coventry, UK. By then I had already observed HOYS targets in the Orion nebula complex from my remote site in Chile for several years. I submitted the images to him via my Google drive and he incorporated the vast amount into the HOYS database. In the meantime, I also added Gaia alert targets (Gaia19eyy and Gaia19fct) to my observing list and submitted to HOYS. Therefore, in total I have submitted more than 30.000 images so far, including the 50.000^th image. More are to come nearly every night. The first results using my data have been written up in Froebrich et al. (2021) and are now published in MNRAS. More articles are in preparation.