Free Astronomy Magazine November-December 2024

47 NOVEMBER-DECEMBER 2024 ASTRO PUBLISHING Hubble found twice as many novae going off near the jet as elsewhere in the giant galaxy during the sur- veyed time period. The jet is launched by a 6.5-billion- solar-mass central black hole sur- rounded by a disk of swirling matter. The black hole, engorged with in- falling matter, launches a 3,000- light-year-long jet of plasma blazing through space at nearly the speed of light. Anything caught in the ener- getic beam would be sizzled. But being near its blistering outflow is apparently also risky, according to the new Hubble findings. The finding of twice as many novae near the jet implies that there are twice as many nova-forming double- star systems near the jet or that these systems erupt twice as often as similar systems elsewhere in the galaxy. “There’s something that the jet is doing to the star systems that wan- der into the surrounding neighbor- hood. Maybe the jet somehow snowplows hydrogen fuel onto the white dwarfs, causing them to erupt more frequently, ” said Lessing. “But it’s not clear that it’s a physical push- ing. It could be the effect of the pressure of the light emanating from the jet. When you deliver hy- drogen faster, you get eruptions faster. Something might be dou- bling the mass transfer rate onto the white dwarfs near the jet.” Another idea the researchers considered is that the jet is heating the dwarf’s companion star, causing it to over- flow further and dump more hydro- gen onto the dwarf. However, the researchers calculated that this heat- ing is not nearly large enough to have this effect. “We’re not the first people who’ve said that it looks like there’s more activity going on around the M87 jet,” said co-investigator Michael Shara of the American Museum of Natural History in New York City. A Hubble Space Telescope image of the giant galaxy M87 shows a 3,000-light-year-long jet of plasma blasting from the galaxy’s 6.5- billion-solar-mass central black hole. The blowtorch-like jet seems to cause stars to erupt along its trajectory. These novae are not caught in- side the jet, but are apparently in a dangerous neighborhood nearby. During a recent 9-month survey, astronomers using Hubble found twice as many of these novae going off near the jet as elsewhere in the galaxy. The galaxy is the home of several trillion stars and thou- sands of star-like globular star clusters. [NASA, ESA, STScI, Alec Lessing (Stanford University), Mike Shara (AMNH) − Ack.: Edward Baltz (Stan- ford University) − Image Processing: Joseph DePasquale (STScI)]