Messier 17 the Swan Nebula

Messier 17, NGC 6618, the Swan or Omega Nebula is a region of star formation located in Sagittarius. 

Astrophotographers Bob and Janice Fera took this photo June 3 to 4, 2013 from Eagle Ridge Observatory in Foresthill, Calif.

CREDIT: Bob and Janice Fera

The Swan Nebula shines in this beautiful night sky image captured by a team of veteran astronomy photographers.

Messier 17, NGC 6618, the Swan or Omega Nebula is a region of star formation located between 5,000 and 6,000 light-years from Earth away in Sagittarius.

The emission nebula glows from the high-energy radiation of bright, young stars deep within the core.

The nebula has many names because it’s said to resemble a swan when inverted, a Greek omega letter and even a horseshoe.

Hubble Observes Glowing, Fiery Shells of Gas in Sagittarius

It may look like something from "The Lord of the Rings," but this fiery swirl is actually a planetary nebula known as ESO 456-67.

Set against a backdrop of bright stars, the rust-colored object lies in the constellation of Sagittarius (The Archer), in the southern sky.

In this image of ESO 456-67, it is possible to see the various layers of material expelled by the central star. Each appears in a different hue - red, orange, yellow, and green-tinted bands of gas are visible, with clear patches of space at the heart of the nebula.

It is not fully understood how planetary nebulae form such a wide variety of shapes and structures; some appear to be spherical, some elliptical, others shoot material in waves from their polar regions, some look like hourglasses or figures of eight, and others resemble large, messy stellar explosions - to name but a few.

Image Credit: ESA/Hubble and NASA

Seeds of Massive Black Holes Found at the Center of the Milky Way

A research team at Keio University, led by Associate Professor Tomoharu Oka, has discovered intermediate-mass black hole (IMBH) candidates at the center of the Milky Way Galaxy.

It is about 30,000 light-years from the solar system in the direction of Sagittarius.

IMBH candidates are considered to be the "seeds" that form and grow massive black holes.

Using radio telescopes, the research team led by Associate Professor Oka has found four "warm, dense (more than 50 degrees Kelvin, more than 10,000 hydrogen molecules per cubic centimeter)" masses of molecular gas at the center of the Milky Way Galaxy. Three of those masses of molecular gas have been expanding.

This research suggests that supernova explosions caused the expansion. It is estimated that the largest explosion that occurred in the masses of molecular gas is equivalent to 200 supernova explosions.

On the other hand, the age of the gas masses is approximately 60,000 years old. Therefore, it can be inferred that a huge star cluster is buried in one of the gas masses.

The mass of the cluster (more than 100,000 times the mass of the sun) is comparable to the largest star cluster found in the Milky Way Galaxy. It is thought that IMBHs are formed within such huge star clusters.

Eventually, IMBHs born near the center of the Milky Way Galaxy form/expand into a supermassive black hole at the nucleus of the galaxy.

Details Many galaxies contain enormous amounts of molecular gas in small areas near their nuclei. Highly condensed molecular gas is a birthplace of lots of stars. Moreover, it is considered to closely relate to activities of galactic nuclei.

Therefore, it is important to investigate the physical state and chemical properties of molecular gas at galaxy centers through observation.

VST Image: Star-forming Region Messier 17 - Omega Nebula

The first released VST image shows the spectacular star-forming region Messier 17, also known as the Omega Nebula or the Swan Nebula, as it has never been seen before. 

This vast region of gas, dust and hot young stars lies in the heart of the Milky Way in the constellation of Sagittarius (The Archer). 

The VST field of view is so large that the entire nebula, including its fainter outer parts, is captured — and retains its superb sharpness across the entire image. 

The data was processed using the Astro-WISE software system developed by E.A. Valentijn and collaborators at Groningen and elsewhere.

Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: OmegaCen/Astro-WISE/Kapteyn Institute

When Galaxies Collide: Feather Merger

The gorgeous collision looks like a delicate sail pushing a small boat through the cosmic ocean.

The object, known as ESO 593-8, is located 650 million light-years away in the constellation Sagittarius.

Image: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)