Polar jets from microquasar SS 433 (background) precess with a period of 162 days. An otherwise inconspicuous gas cloud 100 light years away, known as Fermi J1913+0515, (foreground) pulses at the same frequency, suggesting a direct connection. Image: DESY, Science Communication Lab
Some 15,000 light years from Earth, a huge star with 30 times the mass of the Sun and a black hole weighing in at 10 to 20 solar masses orbit each other every 13 days in a system known as SS 433. The black hole is pulling mass away from the companion star, feeding an off-axis accretion disk and polar jets that wobble, or precess, with a period of about 162 days.
Given its scaled-down resemblance to the supermassive black holes found in the hearts of active galaxies, SS 433 is known as a “microquasar.”
An international team of researchers led by Jian Li, a Humboldt Fellow with Deutsches Elektronen-Synchrotron (DESY), and Diego F. Torres with Spain’s Institute of Space Sciences studied 10 years of observations by NASA’s Fermi gamma ray space telescope and found a gamma-ray signal from a gas cloud some 100 light years from SS 433 that pulsates with the same period.
“Finding such an ...