A Bright Nova in Cassiopeia

What��s that new spot of light in Cassiopeia? A nova. Although novas occur frequently throughout the universe, this nova, known as Nova Cas 2021 or V1405 Cas, became so unusually bright in the skies of Earth last month that it was visible to the unaided eye. Nova Cas 2021 first brightened in mid-March but then, unexpectedly, became even brighter in mid-May and remained quite bright for about a week. The nova then faded back to early-May levels, but now is slightly brightening again and remains visible through binoculars. Identified by the arrow, the nova occurred toward the constellation of Cassiopeia, not far from the Bubble Nebula. A nova is typically caused by a thermonuclear explosion on the surface of a white dwarf star that is accreting matter from a binary-star companion -- although details of this outburst are currently unknown. Novas don't destroy the underlying star, and are sometimes seen to recur. The featured image was created from 14 hours of imaging from Detroit, Michigan, USA. Both professional and amateur astronomers will likely continue to monitor Nova Cas 2021 and hypothesize about details of its cause.

from NASA https://ift.tt/3x3b3fW

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The Galactic Center in Radio from MeerKAT

What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio , the galactic center can be imaged and shows itself to be quite an interesting and active place . The featured picture shows the latest image of our Milky Way's center by the MeerKAT array of 64 radio dishes in South Africa . Spanning four times the angular size of the Moon (2 degrees ), the image is impressively vast, deep, and detailed. Many known sources are shown in clear detail, including many with a prefix of Sgr, since the galactic center is in the direction of the constellation Sagittarius . In our Galaxy's Center lies Sgr A , found here in the image center, which houses the Milky Way's central supermassive black hole. Other sources in the image are not as well understood, including the Arc , just to the left of Sgr A , and numerous filamentary threads....

Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty? The colors result from a mixture of objects and processes. Fine dust -- illuminated by starlight -- produces blue reflection nebulae . Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae . Backlit dust clouds block starlight and so appear dark . Antares , a red supergiant and one of the brighter stars in the night sky , lights up the yellow-red clouds on the upper right of the featured image. The Rho Ophiuchi star system lies at the center of the blue reflection nebula on the left, while a different reflection nebula, IC 4605 , lies just below and right of the image center. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum . from NASA https://ift.tt/fdIYn7J

NGC 1365: Majestic Island Universe

Barred spiral galaxy NGC 1365 is truly a majestic island universe some 200,000 light-years across. Located a mere 60 million light-years away toward the faint but heated constellation Fornax , NGC 1365 is a dominant member of the well-studied Fornax Cluster of galaxies. This sharp color image shows the intense, reddish star forming regions near the ends of the galaxy's central bar and along its spiral arms. Seen in fine detail, obscuring dust lanes cut across the galaxy's bright core. At the core lies a supermassive black hole. Astronomers think NGC 1365's prominent bar plays a crucial role in the galaxy's evolution, drawing gas and dust into a star-forming maelstrom and ultimately feeding material into the central black hole . from NASA https://ift.tt/A0ESVno

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