NGC 4178

NGC 4178: A black hole located in the middle of the spiral galaxy NGC 4178.

One of the lowest mass supermassive black holes ever observed in the middle of a galaxy has been identified, thanks to NASA's Chandra X-ray Observatory and several other observatories. The black hole is located in the middle of the spiral galaxy NGC 4178, shown in this image from the Sloan Digital Sky Survey. The inset shows an X-ray source at the position of the black hole, in the center of a Chandra image. An analysis of the Chandra data, along with infrared data from NASA's Spitzer Space Telescope and radio data from the NSF's Very Large Array suggests that the black hole has a mass less than about 200,000 times that of the sun, near the extreme low-mass end of the supermassive black hole range. The host galaxy is of a type not expected to harbor supermassive black holes, suggesting that this black hole, while related to its supermassive cousins, may have a different origin.

Scale: Main image: 10 arcmin across (about 160,000 light years).

Image credit: X-ray: NASA/CXC/George Mason Univ/N.Secrest et al; Optical: SDSS

Note: For more information, see NGC 4178: Revealing a Mini-Supermassive Black Hole.

The Milky Way

This striking view of the central parts of the Milky Way was obtained with the VISTA survey telescope at ESO’s Paranal Observatory in Chile. This huge picture is 108,500 by 81,500 pixels and contains nearly nine billion pixels. It was created by combining thousands of individual images from VISTA, taken through three different infrared filters, into a single monumental mosaic. These data form part of the VVV public survey and have been used to study a much larger number of individual stars in the central parts of the Milky Way than ever before. Because VISTA has a camera sensitive to infrared light it can see through much of the dust blocking the view for optical telescopes, although many more opaque dust filaments still show up well in this picture.

This image is too large to be easily displayed at full resolution and is best appreciated using the zoom tool. Read about the composition of this 9 gigapixel image in this newsletter.

Image credit: ESO/VVV Survey/D. Minniti
Acknowledgment: Ignacio Toledo, Martin Kornmesser

Notes: For more information, see 84 Million Stars and Counting. For those of you who are download junkies (and The Minister knows there are many of you who), be warned that the full-size original image comes in at a whopping 24.6 gigabytes!

A Planet around Alpha Centauri B

This artist’s impression shows the planet orbiting the star Alpha Centauri B, a member of the triple star system that is the closest to Earth. Alpha Centauri B is the most brilliant object in the sky and the other dazzling object is Alpha Centauri A. Our own Sun is visible to the upper right. The tiny signal of the planet was found with the HARPS spectrograph on the 3.6-meter telescope at ESO’s La Silla Observatory in Chile.

Illustration credit: ESO/L. Calçada/Nick Risinger

Note: For more information, see Planet Found in Nearest Star System to Earth.

Planetary Nebulae

Planetary Nebula Gallery: Four planetary nebulas located less than 5000 light years from Earth.

This gallery shows four planetary nebulas from the first systematic survey of such objects in the solar neighborhood made with NASA's Chandra X-ray Observatory. The planetary nebulas shown here are NGC 6543 (aka the Cat's Eye), NGC 7662, NGC 7009 and NGC 6826. X-ray emission from Chandra is colored purple and optical emission from the Hubble Space Telescope is colored red, green and blue. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. A wind from the hot core rams into the ejected atmosphere, creating the shell-like filamentary structures seen with optical telescopes. The diffuse X-ray emission is caused by shock waves as the wind collides with the ejected atmosphere. The properties of the X-ray point sources in the center of about half of the planetary nebulas suggest that many central stars responsible for ejecting planetary nebulas have companion stars.

Image credit: X-ray: NASA/CXC/RIT/J.Kastner et al.; Optical: NASA/STScI

Note: For more information, see NGC 6543: A Planetary Nebula Gallery.

Spiral Structure Around R Sculptoris

Observations using the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed an unexpected spiral structure in the material around the old star R Sculptoris. This feature has never been seen before and is probably caused by a hidden companion star orbiting the star. This slice through the new ALMA data reveals the shell around the star, which shows up as the outer circular ring, as well as a very clear spiral structure in the inner material.

Image credit: ALMA (ESO/NAOJ/NRAO)/M. Maercker et al.

Note: For more information, see Surprising Spiral Structure Spotted by ALMA.

NGC 2359 - Thor's Helmet Nebula

This VLT image of the Thor’s Helmet Nebula was taken on the occasion of ESO’s 50th Anniversary, 5 October 2012, with the help of Brigitte Bailleul — winner of the Tweet Your Way to the VLT! competition. The observations were broadcast live over the Internet from the Paranal Observatory in Chile. This object, also known as NGC 2359, lies in the constellation of Canis Major (The Great Dog). The helmet-shaped nebula is around 15,000 light-years away from Earth and is over 30 light-years across. The helmet is a cosmic bubble, blown as the wind from the bright, massive star near the bubble's center sweeps through the surrounding molecular cloud.

Photo credit: ESO/B. Bailleul

Note: For more information, see ESO Celebrates its 50th Anniversary.