Fastest-ever star discovered orbiting Milky Way's supermassive black hole (8 percent speed of light)

[muriel_volestrangler]

At the center of our galaxy is Sagittarius A* (Sgr A*), a humongous black hole about four million times the mass of our sun. Being so big, its gravitational effects are extreme and they can be detected by looking at the stars in its immediate vicinity. Orbiting Sgr A* are a handful of stars (and some mysterious objects), locked in a cosmic two-step with the invisible monster, moving at mind-melting speeds.

And astronomers have just discovered the quickest of the lot, clocking its fastest speed around Sgr A* at 8% the speed of light.

A study, published in The Astrophysics Journal on Tuesday, examined the area surrounding Sgr A*, looking for the signature signs of stars. Previous research has discovered dozens of stars moving around the supermassive black hole on highly unusual orbits. This population of stars are known collectively as the S-stars and some of them orbit incredibly close to the black hole, making them difficult to detect.
...
Another star, S4714, is even more extreme. It doesn't quite get as close to Sgr A* as S4711 but it's travelling around the black hole at 8% the speed of light. At that speed, the star is moving about 15,000 miles (~24,000 kilometers) every second, which would mean it could make one full lap of the Earth in just over 1.5 seconds.

https://www.cnet.com/news/fastest-ever-star-discovered-orbiting-milky-ways-supermassive-black-hole/

We present high-pass filtered NACO and SINFONI images of the newly discovered stars S4711–S4715 between 2004 and 2016. Our deep H+K-band (SINFONI) and K-band (NACO) data show the S-cluster star S4711 on a highly eccentric trajectory around Sgr A* with an orbital period of 7.6 yr and a periapse distance of 144 au to the supermassive black hole (SMBH). S4711 is hereby the star with the shortest orbital period and the smallest mean distance to the SMBH during its orbit to date. The used high-pass filtered images are based on coadded data sets to improve the signal to noise. The spectroscopic SINFONI data let us determine detailed stellar properties of S4711 like the mass and the rotational velocity. The faint S-cluster star candidates, S4712–S4715, can be observed in a projected distance to Sgr A* of at least temporarily ?120 mas. From these stars, S4714 is the most prominent, with an orbital period of 12 yr and an eccentricity of 0.985. The stars S4712–S4715 show similar properties, with magnitudes and stellar masses comparable to those of S4711. The MCMC simulations determine confidently precise uncertainties for the orbital elements of S62 and S4711–S4715. The presence of S4711 in addition to S55, S62, and the also newly found star S4714 implies a population of faint stars that can be found at distances to Sgr A* that are comparable to the size of our solar system. These short orbital time period stars in the dense cluster around the SMBH in the center of our Galaxy are perfect candidates to observe gravitational effects such as the periapse shift.

We are excited to announce the detection of a new member of the S-cluster, S4711. This B8/9-V star orbits SgrA* in the center of our Galaxy in around 7.6 years. We found this star during the analysis of S62 (doi: 10.3847/1538-4357/ab5afd, see also ATel #12979). Furthermore, we find indications for a population of fast-moving stars that are at least temporarily inside the orbit of S2. In the related publication (accepted and published via ApJ, doi: 10.3847/1538-4357/ab9c1c, arxiv version will be online soon), we update several values for S62 and establish a method to calculate the mass of a S-cluster member purely on photometric results. All newly discovered stars S4711-S4715 are close to the detection limit and have a calculated mass between 2.0-2.8 M_sun. For S62, we find with this new method a mass of 6.1 M_sun. The star S4714 shows the highest relativistic parameter (r_s/r_p) with 64 compared to 46 of S62. S4711 has a relativistic parameter of 5.6. We are using BONNSAI simulations based on the spectral analysis to derive several parameters for S4711 like e.g., the rotational velocity of 260 +- 25 km/s. We relate the finding of the stars S4711-S4715 to our recent publication about the two disks in the GC (Ali et al. 2020) and confirm, that the major axis is a function of the eccentricity. For S62, we find a pericenter velocity of ~20000 km/s (6.7% of c), for S4711 ~6700 km/s (2.2% of c), and for S4714 ~24000 km/s (8% of c).

http://www.astronomerstelegram.org/?read=13935

[Jarqui]

1. Meanwhile, we've got the slowest massive dark asshole residing

at Pennsylvania Ave, Washington, DC

[Buckeye_Democrat]

2. The author of "The Art of the Deal" described Trump...

... as a black hole.

He also warned that he's a power-hungry sociopath with no attention span, among other problems which have been confirmed repeatedly.

The author, Tony Schwartz, helped to create that monster... but at least he also tried to warn everyone back in 2016.

https://www.newyorker.com/magazine/2016/07/25/donald-trumps-ghostwriter-tells-all/amp

In his journal, Schwartz wrote, “Trump stands for many of the things I abhor: his willingness to run over people, the gaudy, tacky, gigantic obsessions, the absolute lack of interest in anything beyond power and money.” Looking back at the text now, Schwartz says, “I created a character far more winning than Trump actually is.” The first line of the book is an example. “I don’t do it for the money,” Trump declares. “I’ve got enough, much more than I’ll ever need. I do it to do it. Deals are my art form. Other people paint beautifully on canvas or write wonderful poetry. I like making deals, preferably big deals. That’s how I get my kicks.” Schwartz now laughs at this depiction of Trump as a devoted artisan. “Of course he’s in it for the money,” he said. “One of the most deep and basic needs he has is to prove that ‘I’m richer than you.’ ” As for the idea that making deals is a form of poetry, Schwartz says, “He was incapable of saying something like that—it wouldn’t even be in his vocabulary.” He saw Trump as driven not by a pure love of dealmaking but by an insatiable hunger for “money, praise, and celebrity.” Often, after spending the day with Trump, and watching him pile one hugely expensive project atop the next, like a circus performer spinning plates, Schwartz would go home and tell his wife, “He’s a living black hole!”