This barred spiral galaxy, known as UGC 12158, is 400 million light years away, but it resembles our own Milky Way in structure (though it is 40 percent larger). The bright blue star to the lower left of the galaxy’s core is actually a supernova in progress inside the galaxy — SN 2004ef. This image was taken by the Hubble’s Advanced Camera for Surveys through hydrogen alpha and visual filters; light through the yellow filter has been assigned to the green channel. Credit: ESA/Hubble & NASA.
A lovely infrared view of barred spiral galaxy NGC 1365, taken by the HAWK-I infrared camera on ESO’s Very Large Telescope at Paranal Observatory, Chile. NGC 1365 is roughly 60 million light-years away in the constellation Fornax. Image credit: ESO/P. Grosbøl.
M31, the Andromeda Galaxy, and M33, the Triangulum Galaxy, are relatively close to one another, both as they appear in the sky and in actual space (relatively speaking), but it’s interesting to see them in the same photo. Between the two lies Mirach (Beta Andromedae), a red giant star about 10,000 times closer to us than either galaxy. Another fine wide-field view from Rogelio Bernal Andreo, who shot this 3×4 mosaic over eight nights with a Takahashi FSQ-106 apochromatic refractor (plus focal reducer) and an SBIG STL11000 camera through luminance, red, green, blue and hydrogen-alpha filters. Image credit: Rogelio Bernal Andreo (DeepSkyColors.com).
Spiral galaxy NGC 4911, 320 million light years away, resides in the massive Coma Cluster of galaxies in the direction of the constellation Coma Berenices. This image combines data taken by the Hubble Space Telescope’s instruments in 2006, 2007 and 2009, and represents a combined total of 28 hours of exposure time (which brings out the faint wisps of the galaxy’s outer arms). Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA). Acknowledgment: K. Cook (Lawrence Livermore National Laboratory).
The Small Magellanic Cloud, a satellite galaxy of the Milky Way about 200,000 light years away in the southern constellation Tucana, captured by NASA’s Wide-field Infrared Survey Explorer (WISE). In WISE images, each colour represents a different infrared wavelengths: red is 22 µm (microns), green is 12 µm, cyan is 4.6 µm, and blue is 3.4 µm. Credit: NASA/JPL-Caltech/UCLA.
The Antennae Galaxies are impressive enough in visible light, but this composite image combines visible light images from Hubble with an X-ray image from the Chandra X-ray Observatory and an infrared image from the Spitzer Space Telescope. Red is Spitzer’s infrared, taken in December 2003; gold and brown are Hubble’s visible light, taken in July 2004 and February 2005; and blue is Chandra’s X-ray data. Credit: NASA, ESA, SAO, CXC, JPL-Caltech, and STScI. Acknowledgment: G. Fabbiano and Z. Wang (Harvard-Smithsonian CfA, USA), and B. Whitmore (STScI).
Two views of the Sculptor Galaxy, NGC 253, illustrate just how infrared astrophotography can penetrate a galaxy’s dust clouds, revealing cooler stars and this galaxy’s barred spiral structure. The new infrared image, top, was taken with the four-metre VISTA telescope at the European Southern Observatory’s Paranal Observatory in Chile; the visible-light image with the Wide Field Imager on the 2.2-metre MPG/ESO telescope at La Silla. Credit: ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit.
This view of the well-known Whirlpool Galaxy, Messier 51, taken by the Calar Alto Observatory's 1.23-metre Zeiss telescope, is a combination of a standard visual RGB image with a narrowband view of the hydrogen-alpha emission line, which reveals star-forming regions. As you can see, M51 is particularly active, something readily apparent in most images of the galaxy, but this one really emphasizes the H-alpha regions. To create this composite image, a total of 24 hours were exposed through red, green and blue filters for this image, along with an additional 11 hours through a hydrogen-alpha filter, resulting in a combined 35 hours of exposure; click on the photo to see Calar Alto’s separate visual and H-alpha images. Credits: CAHA, Descubre, DSA, OAUV. Vicent Peris (OAUV/DSA/PixInsight), Jack Harvey (SSRO/DSA), Steven Mazlin (SSRO/DSA), Carlos Sonnenstein (Valkànik/DSA) and Juan Conejero (PixInsight/DSA).
NGC 6118, the “Blinking Galaxy” (named because it tends to pop in and out of view in amateur telescopes when using averted vision), is more than 80 million light years away. The European Southern Observatory’s Very Large Telescope (VLT) at Cerro Paranal, Chile, captured this image using its Visible Multi-Object Spectrograph (VIMOS). Credit: ESO.
Here’s NGC 1313, a starburst galaxy in the southern constellation Reticulum some 15 million light years away, as imaged by the Gemini Observatory's Gemini South eight-metre telescope in Chile. This is a narrowband image, in which each colour represents a different emission line: red is hydrogen-alpha (656.3 nanometres), green is oxygen-III (500.7 nm), and blue is helium-II (468.6 nm). Unlike many other narrowband images, this is also a true-colour image (in that hydrogen-alpha is red, helium is blue, and so on). It’s also unusual to see an emission-line narrowband image of a galaxy; in this case, it’s done to highlight star-formation regions. Credit: Gemini Observatory/AURA/Travis Rector (University of Alaska, Anchorage). Via Astronomy Now.