NGC 6814


A spiral snowflakeThis worth posting simply because it’s pretty.

NGC 6814 is an intermediate spiral galaxy in constellation Aquila located about 75 million light years from Earth. It’s a Seyfert galaxy with an extremely bright nucleus powered by a supermassive black hole with roughly 10 millions times the mass of the Sun. The galaxy is also a highly variable source of X-ray radiation. UV and optical emission also vary, although more smoothly, with time lag of two days behind the x-ray output.

Image Credit: ESA / NASA

A Seyfert Galaxy


NGC 5793Carl Seyfert was an interesting fellow. Back in the ’50s when I was a kid growing up in Nashville, he was Director of the Dyer Observatory at Vanderbilt University. I met him through the local astronomy club associated with the Nashville Children’s Museum. He was well known around town because he moonlighted as the weatherman for WSM-TV. He was known in astronomical circles for his research on a class of galaxies.

Those galaxies have incredibly luminous centers that we believe are caused by supermassive black holes—black holes that can be billions of times the mass of the sun—pulling in and swallowing gas and dust from their surroundings. NGC 5793 is a Seyfert galaxy over 150 million light-years away in the constellation of Libra.

This Hubble image is centered on NGC 5793. This galaxy is of great interest to astronomers for many reasons. For one, it appears to house objects known as masers. Whereas lasers emit visible light, masers emit microwave radiation. The term “maser” is an acronym of Microwave Amplification by Stimulated Emission of Radiation. Lasers emit visible light; masers emit microwave radiation. Maser emission occurs when particles absorb energy from their surroundings re-emit the energy in the microwave part of the spectrum. Naturally occurring masers such as are found in NGC 5793 can tell us a lot about their environment; we see some types of masers in areas where stars are forming. In NGC 5793 there are also intense mega-masers, thousands of times more luminous than the sun.

Image Credit: NASA / ESA

What’s in a Name?


This galaxy is called 2XMM J143450.5+033843. That may seem like some random collection characters, but the name is meaningful to an astronomer. The first four characters show that it was discovered during the second sky survey performed by ESA’s XMM-Newton satellite—2XMM.  The characters following the J are its address in the sky: a right ascension of 14h (hours) 34m (minutes) 50.5s (seconds) and a declination of +03d (degrees) 38m (minutes) 43s (seconds).

2XMM J143450.5+033843 is almost 400 million light-years from Earth. It is a Seyfert galaxy that is dominated by a supermassive black hole that is pumping out vast amounts of radiation from its galactic core.

Image Credit: ESA / NASA

Messier 106


Messier 106 also known as NGC 4258 is an intermediate spiral galaxy about 22 to 25 million light-years away from Earth. It is also a Seyfert II galaxy. X-rays and unusual emission lines have been detected coming from M106, leading astronomers to suspect that part of the galaxy is falling into a supermassive black hole in the center. A Type II supernova was observed in this galaxy in May, 2014. A Type II supernova is caused by a the rapid collapse and subsequent violent explosion of a massive star.

Image Credit: NASA / ESA

NGC 1097


NGC 1097NGC 1097 is a barred spiral galaxy. It’s also a Seyfert galaxy. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. Seen in visible light, most Seyfert galaxies look like normal spiral galaxies, but when studied in other wavelengths, the luminosity of their cores is of comparable intensity to that of entire galaxies the size of the Milky Way.

Dwarf elliptical galaxy NGC 1097A is a peculiar elliptical galaxy that orbits 42,000 light-years from the center of NGC 1097

Image Credit: ESO

A Seyfert Galaxy


NGC 5793Carl Seyfert was an interesting fellow. Back in the ’50s when I was a kid growing up in Nashville, he was Director of the Dyer Observatory at Vanderbilt University. I met him through the local astronomy club associated with the Nashville Children’s Museum. He was well known around town because he moonlighted as the weatherman for WSM-TV. He was known in astronomical circles for his research on a class of galaxies.

Those galaxies have incredibly luminous centers that we believe are caused by supermassive black holes—black holes that can be billions of times the mass of the sun—pulling in and swallowing gas and dust from their surroundings. NGC 5793 is a Seyfert galaxy over 150 million light-years away in the constellation of Libra.

This Hubble image is centered on NGC 5793. This galaxy is of great interest to astronomers for many reasons. For one, it appears to house objects known as masers. Whereas lasers emit visible light, masers emit microwave radiation. The term “maser” is an acronym of Microwave Amplification by Stimulated Emission of Radiation. Lasers emit visible light; masers emit microwave radiation. Maser emission occurs when particles absorb energy from their surroundings re-emit the energy in the microwave part of the spectrum. Naturally occurring masers such as are found in NGC 5793 can tell us a lot about their environment; we see some types of masers in areas where stars are forming. In NGC 5793 there are also intense mega-masers, thousands of times more luminous than the sun.

Image Credit: NASA