NASA's Wide-field Infrared Survey Explorer, or WISE, captured this colorful image of the nebula BFS 29 surrounding the star CE-Camelopardalis, found hovering in the band of the night sky comprising the Milky Way. Most of the gas and dust in this image cannot be seen directly in visible light, but WISE's detectors revealed exquisite new details, and even some hidden stars.
The nebulous interstellar gas and dust in this image is known as BFS 29. "BFS" stands for Blitz, Fich, and Stark -- the three astronomers who identified and cataloged 65 new star-forming regions in 1982 (the "29" simply means that it's the 29th object in their catalog). In visible light, BFS 29 can be seen, but only very slightly. This is because the dust scatters and reflects some of the light from nearby stars, hence its classification as a reflection nebula. The gas in BFS 29 also contains large amounts of ionized hydrogen -- referred to by astronomers as "H II." Hence, the nebula is also classified as an HII region. Reflection nebulae and HII regions are often associated with star formation.
Most of the illumination and energy in BFS 29 is likely provided by the star CE-Camelopardalis. The "CE" in its name comes from a complex naming system for variable stars. Camelopardalis is the name of the constellation in which it is found, and means giraffe in Latin (from a camel wearing a leopard's coat). Of the three brightest stars in this image, it is the bright pink-colored star nearest to the center of the image. The other two bright stars cannot be seen in visible light; they are hidden behind the clouds of gas and dust. In infrared light, however, they shine through brilliantly. CE-Camelopardalis is a variable supergiant star, which means it will eventually end its life in a supernova, likely leaving behind a black hole. It is near the giraffe's hind foot, making a sort of ankle bracelet, as compared to the emerald necklace featured in the November 9, 2010 image.
All four of WISE's infrared detectors were used to make this image. The colors used represent specific wavelengths of infrared radiation. Blue and blue-green (cyan) represent 3.4- and 4.6-micron light, respectively. These wavelengths are mainly emitted by stars within the Milky Way. Green represents 12-micron light, which is emitted by the warm gas of the nebulae. Red represents the longest wavelength, 22-micron light emitted by cooler dust within the nebulae.
Photo credit: NASA/JPL-Caltech/UCLA
The Cassini spacecraft looks past the cratered south polar area of Saturn's moon Rhea to spy the moon Dione and the planet's rings in the distance.
Dione's "wispy" terrain can be seen on the trailing hemisphere of that moon. See PIA10560 to learn more.
This view looks toward the south polar area of the anti-Saturn side of Rhea (1,528 kilometers, or 949 miles across) and the Saturn-facing side of Dione (1,123 kilometers, or 698 miles across). North on the moons is up.
This view looks toward the northern, sunlit side of the rings from just above the ringplane. The rings, closer to Cassini than Dione is, obscure the view of the south of Dione.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on January 11, 2011. The view was acquired at a distance of approximately 61,000 kilometers (38,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 15 degrees. The view was acquired at a distance of approximately 924,000 kilometers (574,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 15 degrees. Image scale is 358 meters (1,175 feet) per pixel on Rhea and 6 kilometers (4 miles) per pixel on Dione.
Photo credit: NASA/JPL/Space Science Institute
The nebula Messier 78 takes center stage in this image taken with the Wide Field Imager on the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile, while the stars powering the bright display take a backseat. The brilliant starlight ricochets off dust particles in the nebula, illuminating it with scattered blue light. Igor Chekalin was the overall winner of ESO’s Hidden Treasures 2010 astrophotography competition with his image of this stunning object.
Messier 78 is a fine example of a reflection nebula. The ultraviolet radiation from the stars that illuminate it is not intense enough to ionize the gas to make it glow — its dust particles simply reflect the starlight that falls on them. Despite this, Messier 78 can easily be observed with a small telescope, being one of the brightest reflection nebulae in the sky. It lies about 1350 light-years away in the constellation of Orion (The Hunter) and can be found northeast of the easternmost star of Orion’s belt.
This new image of Messier 78 from the MPG/ESO 2.2-meter telescope at the La Silla Observatory is based on data selected by Igor Chekalin in his winning entry to the Hidden Treasures competition [1].
The pale blue tint seen in the nebula in this picture is an accurate representation of its dominant color. Blue hues are commonly seen in reflection nebulae because of the way the starlight is scattered by the tiny dust particles that they contain: the shorter wavelength of blue light is scattered more efficiently than the longer wavelength red light.
This image contains many other striking features apart from the glowing nebula. A thick band of obscuring dust stretches across the image from the upper left to the lower right, blocking the light from background stars. In the bottom right corner, many curious pink structures are also visible, which are created by jets of material being ejected from stars that have recently formed and are still buried deep in dust clouds.
Two bright stars, HD 38563A and HD 38563B, are the main powerhouses behind Messier 78. However, the nebula is home to many more stars, including a collection of about 45 low mass, young stars (less than 10 million years old) in which the cores are still too cool for hydrogen fusion to start, known as T Tauri stars. Studying T Tauri stars is important for understanding the early stages of star formation and how planetary systems are created.
Remarkably, this complex of nebulae has also changed significantly in the last ten years. In February 2004 the experienced amateur observer Jay McNeil took an image of this region with a 75 mm telescope and was surprised to see a bright nebula — the prominent fan shaped feature near the bottom of this picture — where nothing was seen on most earlier images. This object is now known as McNeil’s Nebula and it appears to be a highly variable reflection nebula around a young star.
This color picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through an H-alpha filter that shows light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively.
Notes:
[1] Igor Chekalin from Russia uncovered the raw data for this image of Messier 78 in ESO’s archives in the competition Hidden Treasures (eso1102). He processed the raw data with great skill, claiming first prize in the contest for his final image (Flickr link). ESO’s team of in-house image processing experts then independently processed the raw data at full resolution to produce the image shown here.
Photo credit: ESO, Igor Chekalin
