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Explanation: This beautiful cosmic cloud is a popular stop on telescopic tours of the constellation Sagittarius. Eighteenth century cosmic tourist Charles Messier cataloged the bright nebula as M8. Modern day astronomers recognize the Lagoon Nebula as an active stellar nursery about 5,000 light-years distant, in the direction of the center of our Milky Way Galaxy. Hot stars in the embedded open star cluster NGC 6530 power the nebular glow. Remarkable features can be traced through this sharp picture, showing off the Lagoon's filaments of glowing gas and dark dust clouds. Twisting near the center of the Lagoon, the small, bright...

Explanation: The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid illustrates three different types of astronomical nebulae; red emission nebulae dominated by light emitted by hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. The bright red emission region, roughly separated into three parts by obscuring dust lanes, lends the Trifid its popular name. But in this sharp, colorful scene,...

Earth's Milky Way Neighborhood Gets More Respect Old picture: Local Arm a small "spur" of Milky Way. New picture: Local Arm probable major branch of Perseus Arm. CREDIT: Robert Hurt, IPAC; Bill Saxton, NRAO/AUI/NSF. Our Solar System's Milky Way neighborhood just went upscale. We reside between two major spiral arms of our home galaxy, in a structure called the Local Arm. New research using the ultra-sharp radio vision of the National Science Foundation's Very Long Baseline Array (VLBA) indicates that the Local Arm, previously thought to be only a small spur, instead is much more like the adjacent major arms,...

If you imagine the Milky Way as a rippled cookie, our star is in a neighborhood in between two big ripples (the Sagittarius Arm and the Perseus Arm). Before, we thought the Local Arm (or Orion Arm) was just a small spur between the arms. New research using trigonometric parallax measurements, however, suggests the Local Arm could be a “significant branch” of one of those two arms. In a few words, our stellar neighborhood is a bigger and brighter one than we thought it was.

Explanation: The Eagle Nebula and the Swan Nebula span this broad starscape, a telescopic view of the Sagittarius spiral arm toward the center of our Milky Way galaxy. The Eagle, also known as M16, is left, above center, and the Swan, or M17 at the lower right. The deep, wide-field image shows the cosmic clouds as brighter regions of active star-formation. They lie along the spiral arm suffused with reddish emission charactistic of atomic hydrogen gas, and dusty dark nebulae. In fact, the center of both nebulae are locations of well-known close-up images of star formation from the Hubble Space...

Explanation: Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this degree wide field of view spans almost 100 light-years. The sharp, composite, color image utilizing data from space and ground based telescopes, follows faint details of the region's gas and dust clouds against a backdrop of central Milky Way stars. Stellar winds and energetic light from hot, massive stars formed from M17's stock of cosmic gas and dust have slowly carved away at the remaining interstellar material producing the cavernous appearance and...

Explanation: Clouds of glowing gas mingle with dust lanes in the Trifid Nebula, a star forming region toward the constellation of the Archer (Sagittarius). In the center, the three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the right, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, also known as M20, is only about 300,000 years old, making it among the youngest emission nebulae known. The nebula lies about 9,000...

Explanation: Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds emanating from the central stars, visible in the center, have been measured in excess of 1000 kilometers per second. These winds expand the nebula, flow along the nebula's walls, and cause waves of hot gas...

Explanation: These three bright nebulae are often featured in telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula left of center, and colorful M20 on the right. The third, NGC 6559, is above M8, separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. The expansive M8, over a hundred light-years across, is also known as the Lagoon Nebula. M20's popular moniker is the Trifid. Glowing...

Explanation: From Sagittarius to Scorpius, the central Milky Way is a truly beautiful part of planet Earth's night sky. The gorgeous region is captured in this wide field image spanning about 30 degrees. The impressive cosmic vista, taken in 2010, shows off intricate dust lanes, bright nebulae, and star clusters scattered through our galaxy's rich central starfields. Starting on the left, look for the Lagoon and Trifid nebulae, the Cat's Paw, while on the right lies the Pipe dark nebula, and the colorful clouds of Rho Ophiuchi and Antares (right). The actual center of our Galaxy lies about 26,000 light...

PARIS (AFP) - A black hole slumbering at the centre of our galaxy went into a "feeding frenzy" three centuries ago, the European Space Agency (ESA) said on Tuesday. Located around 26,000 light years from Earth, the black hole, known as Sagittarius A-star (Sgr A*), is a monster with a mass four million times that of the Sun. Japanese astronomers, using ESA's XMM-Newton orbital telescope and US and Japanese X-ray satellites, discovered that clouds of gas brightened and faded in X-ray light when they passed near Sgr A*'s maw, ESA said in a press release. The phenomenon is due to...

In a cosmic game of pinball, black holes fling high-energy protons into space, where they zigzag around at near light-speeds before smashing into low-energy protons, finds a new study. Then the collisions send bursts of gamma rays flying out from the center of our galaxy, which explains for the first time the mechanism for the high-energy jets first spotted in 2004. This proton-slinging could explain more than this cataclysmic light show deep in our galaxy. The scientists suggest other black holes in the universe could rely on the pinball mechanism to produce enormous jets of light. “Our galaxy's central supermassive...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 September 30 The Sagittarius Dwarf Tidal Stream Drawing Credit & Copyright: David Martinez-Delgado (MPIA) & Gabriel Perez (IAC) Explanation: Is our Milky Way Galaxy out to lunch? Recent wide field images and analyses now indicate that our home galaxy is actually still in the process of devouring its closest satellite neighbor. This unfortunate neighbor, the Sagittarius Dwarf galaxy, is now seen to be part of a larger...

Our Milky Way galaxy is gobbling up its galactic neighbor, Sagittarius, and on Wednesday, scientists offered documentary proof of this continuing cosmic cannibalism. Astronomers have mapped the Sagittarius galaxy to show in detail how its debris wrap around and pass through the Milky Way, which contains Earth. On its way to oblivion, the dwarf Sagittarius -- which is about 10,000 times the mass of the Milky Way -- is getting stretched, torn apart and ultimately eaten, scientists at the University of Virginia and the University of Massachusetts reported. "It's clear who's the bully in the interaction," Steven Majewski of the...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 March 4 In the Center of the Lagoon Nebula Credit: A. Caulet (ST-ECF, ESA), NASA Explanation: The center of the Lagoon Nebula is busy with the awesome spectacle of star formation. Visible in the lower left, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. The tremendously bright nearby star, Hershel 36, lights...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 December 23 Stars and Dust Through Baade's Window Credit & Copyright: David Malin (AAO), ROE, UKS Telescope Explanation: Billions of stars light up the direction toward the center of our Galaxy. The vast majority of these stars are themselves billions of years old, rivaling their home Milky Way Galaxy in raw age. These stars are much more faint and red than the occasional young blue stars that...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 December 10 M17: Omega Nebula Star Factory Credit & Copyright: Jean-Charles Cuillandre (CFHT), Hawaiian Starlight, CFHT Explanation: In the depths of the dark clouds of dust and molecular gas known as M17, stars continue to form. The similarity to the Greek letter capital Omega gives the molecular cloud its popular name, but the nebula is also known as the Swan Nebula, the Horseshoe Nebula, and M17. The...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 October 18 At the Center of the Milky Way Credit: Rainer Schödel (MPE) et al., NACO, ESO Explanation: At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually inescapable and based on observations of stars orbiting very near the galactic center. Using one of the...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 October 6 The Lagoon Nebula in Three Colors Credit: R. Barba, N. Morrell et al. (UNLP), CTIO, NOAO, NSF Explanation: The bright Lagoon Nebula is home to a diverse array of astronomical objects. Particularly interesting sources include a bright open cluster of stars and several energetic star-forming regions. When viewed by eye, cluster light is dominated by an overall red glow that is caused by luminous hydrogen...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 September 18 A Sagittarius Starscape Credit & Copyright: David Malin (AAO), ROE, UKS Telescope Explanation: Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of stars, dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun. Next huge filaments of dark interstellar dust run across the image...