A strangely complex galaxy located a billion light years from Earth

There is an active galaxy called BL Lacertae located about a billion light-years away, and it has a strange twist at its center.

Exploring the universe is of great importance, not only because of human curiosity and our need to see what’s out there, but also because by studying distant stars and galaxies, we can learn more about ourselves and how galaxies such as the Milky Way came into being and what the future holds for them.

Thanks to state-of-the-art observatories like the James Webb Space Telescope, we are closer than ever to unraveling some of the greatest mysteries in astrophysics, but also to discovering new ones. But James Webb isn’t the only observatory astronomers rely on to explore the vastness of deep space. The BL Lacertae ( BL Lac ) galaxy was recently studied by 86 scientists from 13 countries using high-resolution optical tracking.

Using the 0.9-meter Reflecting Telescope at BYU’s West Mountain Observatory , Dr. Mike Joner and BYU undergraduate student Gilvan Apolonio captured more than 200 observations of the galaxy. In a collaborative project called Whole Earth Blazar Telescope (WEBT), their measurements were combined with observations made by scientists around the world. When an object exhibits high variability, the WEBT network allows it to be monitored from different locations, 24 hours a day.

Scientists have found that BL Lac’s central jet exhibits surprisingly rapid changes in brightness, based on WEBT observations made during the summer of 2020. A twist in the jet’s magnetic field could be the cause of these cycles. changes in brightness. West Mountain Observatory, a ground-based BYU telescope, was among 37 global observatories that monitored optical variations in BL Lac, an active galaxy about 1 billion light-years away. While working at the observatory in the spring and summer of 2020, Joner and Apolonio alternated night shifts. It was necessary to work an atypical schedule since the observations had to take place every clear night and there were no other trained student observers in Provo.

In order to understand the high-energy observations of the Gamma-Ray Fermi telescope, it was crucial to analyze the high-speed optical observations. It is essential to combine data from high-energy space observatories with information from ground-based optical monitoring stations. Space telescopes costing billions of dollars are often used for such projects, Joner said. A comparison between the high-energy observations and the ground light curves confirmed that the high-energy observations showed rapid periodic oscillations.

Despite his established expertise in astrophysical research, Joner is still amazed at the amount of detail scientists are able to glean from such observations. “It is striking to see the variations of a blazar’s central jet so clearly on a galactic scale, even when combined with the light from hundreds of billions of stars in its host galaxy,” he said. . The variability of the jet is easily visible although it is accompanied by light from hundreds of billions of stars.

The modestly sized and well-equipped facilities at BYU, like those we have at BYU, can always be counted on to explore the unknown reaches of the universe in our age of giant telescopes and space research, it says. in a press release. The study was published in the journal Nature .

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