Sky watchers were stunned to see three cosmic phenomena at once last night. On February 25, the sky for a short time in the region of the constellation Ursa Major occurred a random astronomical event, namely, a mysterious 'triangle' was visible.
Astronomers have noted three different objects at once within the Big Dipper – the green comet ATLAS, the blue Owl Nebula and the Snowboard galaxy. Here's what the Space Weather website reported:
'Deep inside the Big Dipper, a strange triangle appeared. It only lasted a few hours, but Gerald Riemann was ready and photographed him from his backyard in Eichgraben, Austria. '
The summits were a green comet, a blue nebula, and a silvery galaxy. This triangle appeared, for a very brief moment, when the comet ATLAS (C / 2019 Y4) flew past the Owl Nebula (M97) and the Snowboard Galaxy (M108) on February 25.
On May 31, 2020, the comet ATLAS will approach the orbit of Mercury and will be at a distance of 0.25 AU. from the sun. Astronomers have seen the comet do this before.
The orbit of ATLAS is similar to the orbit of the Great Comet of 1844, which was visible in broad daylight as it passed very close to the sun in the 19th century. Astronomers speculate that ATLAS may be a fragment of this Great Comet.
Another object, the Planetary Owl Nebula, was created by an aging star about eight times the mass of the Sun. The star is constantly losing its outer layers. Ultraviolet radiation from the star's core causes the gas 'envelope' to glow, expanding outward.
After the nebula disappears, only its center remains in the form of a hot and very dense 'white dwarf', which will slowly cool down over millions of years.
The Snowboard Galaxy is located 45.99 million light years from Earth and is 13.27 billion years old. It is almost as old as the universe itself.
At the center of M108 is a supermassive black hole with a mass 24 million times that of the Sun. The Chandra X-ray Observatory detected in M108 with multiple X-ray sources, with the brightest X-ray source being a medium-sized black hole actively accreting material.
M108 is one of the largest and brightest members of the Ursa Major Cluster, and is also part of the Virgo Supercluster of galaxies. The galaxy is located directly under the bowl of the Big Dipper. M108 can be seen even with a small telescope. The best time to see M108 is April.
