Students at the New York University Abu Dhabi, along with their supervisor, David Russell, have used data gathered from Faulkes Telescope Project observations to observe the strange behaviour of a binary star system containing a black hole.

The system, known as Swift J1753.5-0127, has been a target of a 12 year monitoring campaign of 40 such objects run by Dr Russell and Fraser Lewis of the FT Team. Since 2005, this object has displayed an ‘outburst’ at optical wavelengths believed to be caused by the transferring of stellar material from a normal star to its more exotic binary companion. Typically, these outbursts last for days or months so this system was already earmarked for its longevity, having been active for over 11 years.

In recent days, in the data studied by the students, the system has been observed to ‘switch off’ perhaps indicative of a cessation of this long period of mass transfer. The two undergraduates have been able to analyse these data and contribute to a publication known as an Astronomer’s Telegram in conjunction with astronomers based at the Universities of Alberta and Southampton.

One student, Ahlam Abdulghafoor Al Qasim, said “Analyzing and monitoring this black hole was a very exciting and enlightening experience at the same time. Extracting the magnitudes from each optical image, I was surprised to see that the black hole was dramatically getting dimmer and fainter. It will be very exciting to gather multi-wavelength observations on the source before it completely fades away.

Her fellow student, Aisha AlMannaei added “We managed to learn how to do photometry, and were surprised to see that there was a dramatic drop in the magnitude of the source in the last 2 months. We hope to get more data after publishing our ATel to have a better estimate of the black hole as it decays into quiescence.”

Read the ATel and see the plots