According to researchers, an unusual source of light that they assume to be a huge star or black hole kicked out of a galaxy, has been discovered some 90 million light-years away. On the other hand it could be a giant star exploding over an exceptionally long period of time – at least several decades. Anyhow, one thing is certain: this mysterious object is something quite intriguing, a source of unstoppable interest for physicists all over the world due to its potential to provide experimental confirmation of the much-discussed gravitational waves predicted by Albert Einstein.
The dwarf galaxy Markarian 177 and its unusual source SDSS1133 both lie 90 million light-years away. The galaxies are located in the bowl of the Big Dipper, a well-known star pattern in the constellation Ursa Major. SDSS1133 may be the remnant of a massive star that erupted for a record period of time before destroying itself in a supernova explosion.
“With the data we have in hand, we can’t yet distinguish between these two scenarios,”
said lead researcher Michael Koss, an astronomer at ETH Zurich, the Swiss Federal Institute of Technology.
“One exciting discovery made with NASA’s Swift is that the brightness of SDSS1133 has changed little in optical or ultraviolet light for a decade, which is not something typically seen in a young supernova remnant.”
Koss and his colleagues report that the source has brightened significantly in visible light during the past six months. This is generally a trend that, if maintained, would sustain the black hole interpretation. Unlike a typical black hole, it wasn’t located in its galaxy’s core. In fact, it was around 2,600 light-years out of place.
So the researchers think they’re seeing the aftermath of the collision of two galaxies, a crash that sent one of their black holes out into space. If two colliding galaxies each have a supermassive black hole, those black holes can merge. Furthermore this merger produces massive gravitational waves (ripples in the very fabric of space-time). This force can cause the new black hole to recoil, kicking it out of center and into a wonky orbit. But it’s theoretically possible for the black hole to be ejected from the galaxy entirely, as shown in a video simulation.
Apart from being a probable wayward black hole, SDSS1133 could be a rare star called a Luminous Blue Variable (LBV). An LBV is a massive star whose regular eruptions hurl matter and energy through space before it explodes into a giant supernova. But if SDSS1133 is an LBV and its eruptions had lasted from 1950 to 2001, this would have been the longest recorded event of this kind.
In order to analyze the object in greater detail, the team is planning ultraviolet observations with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope in October 2015.