All articles tagged with #sgr a
Astronomers using the GRAVITY instrument on the Very Large Telescope have identified S301, a star on an extremely eccentric orbit that dives to within about 11 AU of the Milky Way's central black hole, Sgr A*. At its closest it speeds around 0.08c, offering a rare opportunity to measure the black hole's spin and to probe its geometry and other properties with future observations.
A radio feature long thought to tower over the Milky Way’s center is revealed to be a foreground, closed shell of ionized hydrogen about 6,520 light-years away and 115 light-years across. Optical spectroscopy across the structure shows coherent gas motion and excitation by young stars (photoionisation), consistent with a normal H II region rather than a nuclear outflow from Sagittarius A*. Distance was estimated via dust reddening and 3D dust maps, aligning with 2024 work that placed the lobe in the foreground. While large-scale Milky Way structures like the Fermi bubbles remain, this finding highlights how line-of-sight overlap can mimic connections near the Galactic Center.
Scientists suspect a rapidly spinning, highly magnetic neutron star (a pulsar) sits near the Milky Way’s center. A Breakthrough Listen radio survey with the Green Bank Telescope (2021–2023) found a single pulsar candidate, BLPSR, around 122 rotations per second. If confirmed, such a pulsar orbiting Sagittarius A* could serve as a precise cosmic clock to test general relativity in the extreme gravity near the galaxy’s supermassive black hole, though the Galactic Center is notoriously hard to survey. Future facilities like ngVLA and SKA could help determine how many pulsars truly populate the core.
The Event Horizon Telescope has captured the first view of polarized light and magnetic fields surrounding Sagittarius A* (Sgr A*), the supermassive black hole at the heart of the Milky Way, revealing similarities with the magnetic fields around the supermassive black hole in the galaxy M87. This suggests that strong and well-organized magnetic fields could be common to all black holes and hints at the possibility of a hidden and faint jet around Sgr A*. The findings provide compelling evidence that strong magnetic fields are ubiquitous to these cosmic titans and could influence our understanding of how galaxies evolve.
Astronomers have potentially discovered an extragalactic star, named S0–6, among the stars orbiting the supermassive black hole at the center of the Milky Way, Sagittarius A*. The star's chemical composition suggests it originated in a small satellite galaxy of the Milky Way that was cannibalized billions of years ago. If confirmed, this would make S0–6 the first extragalactic star found near Sgr A*. Further investigation is needed to unravel the mysteries of these stars near the supermassive black hole.