Astronomers have studied galactic evolution for decades, gradually improving our knowledge of how galaxies have changed over cosmic history. The NASA/ESA Hubble Space Telescope has played a big part in this, allowing astronomers to see further into the distance, and hence further back in time, than any telescope before it – capturing light that has taken billions of years to reach us.
Looking further into the very distant past to observe younger and younger galaxies is very valuable, but it is not without its problems for astronomers. All newly-born galaxies lie very far away from us and appear very small and faint in the images. On the contrary, all the galaxies near to us appear to be old ones.
DDO 68, captured here by the NASA/ESA Hubble Space Telescope, was one of the best candidates so far discovered for a newly-formed galaxy in our cosmic neighbourhood. The galaxy lies around 39 million light-years away from us; although this distance may seem huge, it is in fact roughly 50 times closer than the usual distances to such galaxies, which are on the order of several billions of light years.
Far beyond the stars in the constellation of Leo (The Lion) is irregular galaxy IC 559.
IC 559 is not your everyday galaxy. With its irregular shape and bright blue spattering of stars, it is a fascinating galactic anomaly. It may look like sparse cloud, but it is in fact full of gas and dust which is spawning new stars.
Discovered in 1893, IC 559 lacks the symmetrical spiral appearance of some of its galactic peers and not does not conform to a regular shape. It is actually classified as a “type Sm” galaxy — an irregular galaxy with some evidence for a spiral structure.
Irregular galaxies make up about a quarter of all known galaxies and do not fall into any of the regular classes of the Hubble sequence. Most of these uniquely shaped galaxies were not always so — IC 559 may have once been a conventional spiral galaxy that was then distorted and twisted by the gravity of a nearby cosmic companion.
This image, captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3, combines a wide range of wavelengths spanning the ultraviolet, optical, and infrared parts of the spectrum.
The destructive results of a mighty supernova explosion reveal themselves in a delicate blend of infrared and X-ray light, as seen in this image from NASA’s Spitzer Space Telescope and Chandra X-Ray Observatory, and the European Space Agency’s XMM-Newton.
The bubbly cloud is an irregular shock wave, generated by a supernova that would have been witnessed on Earth 3,700 years ago. The remnant itself, called Puppis A, is around 7,000 light-years away, and the shock wave is about 10 light-years across.
The pastel hues in this image reveal that the infrared and X-ray structures trace each other closely. Warm dust particles are responsible for most of the infrared light wavelengths, assigned red and green colors in this view. Material heated by the supernova’s shock wave emits X-rays, which are colored blue. Regions where the infrared and X-ray emissions blend together take on brighter, more pastel tones.
The shock wave appears to light up as it slams into surrounding clouds of dust and gas that fill the interstellar space in this region.
From the infrared glow, astronomers have found a total quantity of dust in the region equal to about a quarter of the mass of our sun. Data collected from Spitzer’s infrared spectrograph reveal how the shock wave is breaking apart the fragile dust grains that fill the surrounding space.
Supernova explosions forge the heavy elements that can provide the raw material from which future generations of stars and planets will form. Studying how supernova remnants expand into the galaxy and interact with other material provides critical clues into our own origins.
Infrared data from Spitzer’s multiband imaging photometer (MIPS) at wavelengths of 24 and 70 microns are rendered in green and red. X-ray data from XMM-Newton spanning an energy range of 0.3 to 8 kiloelectron volts are shown in blue.
NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.
This image shows NGC 121, a globular cluster in the constellation of Tucana (The Toucan). Globular clusters are big balls of old stars that orbit the centers of their galaxies like satellites — the Milky Way, for example, has around 150.
NGC 121 belongs to one of our neighboring galaxies, the Small Magellanic Cloud (SMC). It was discovered in 1835 by English astronomer John Herschel, and in recent years it has been studied in detail by astronomers wishing to learn more about how stars form and evolve. Continue reading →
If you venture over to the ESA site you can see a Hi-res version of this beauty.
This view, captured by the NASA/ESA Hubble Space Telescope, shows a nearby spiral galaxy known as NGC 1433. At about 32 million light-years from Earth, it is a type of very active galaxy known as a Seyfert galaxy — a classification that accounts for 10% of all galaxies. They have very bright, luminous centres comparable to that of our galaxy, the Milky Way.
NASA’s NEOWISE mission captured this series of pictures of comet C/2012 K1 — also known as comet Pan-STARRS — as it swept across our skies on May 20, 2014. The comet is relatively close to us — it was only about 143 million miles (230 million kilometers) from Earth when this picture was taken. It is seen passing a much more distant spiral galaxy, called NGC 3726, which is about 55 million light-years from Earth, or 2 trillion times farther away than the comet.
NGC 4258 is also known as M106 for being the 106th entry into Charles Messiers famous catalog. The galaxy is visible in optical light so you can see it with some help of course, at a mag 8.4 a small telescope should do. Have a look in Canes Venatici – more specifically RA=12 19.0, Dec=+47 18.
A composite image of the spiral galaxy NGC 4258 showing X-ray emission observed with NASA’s Chandra X-ray Observatory (blue) and infrared emission observed with NASA’s Spitzer Space Telescope (red and green).
The infrared emission is produced by hydrogen molecules. A labeled version of the image shows the direction of radio jets, along with the location of the supermassive black hole driving these jets and “hotspots,” where the jets are striking gas in the galaxy. The X-ray and hydrogen emission are both thought to be caused by shocks, similar to a sonic boom from a supersonic plane. The similarity in location between the X-ray and hydrogen emission and the radio jets implies that the jets have caused the shocks. Continue reading →
The subject of this Hubble image is NGC 5474, a dwarf galaxy located 21 million light-years away in the constellation of Ursa Major (The Great Bear). This beautiful image was taken with Hubble’s Advanced Camera for Surveys (ACS). Continue reading →
Perseus A (aka NGC 1275) is 72.7 Mpc (237 million light-years) away in the constellation Perseus of all places.
Perseus is located at RA: 03h 25m 20.601s Dec: +49°54’29.118″,actually the location of Mirfak, the alpha star which means it is the brightest star in the constellation. Easily visible in the northern sky, it is home to the Double Cluster, a pair of open clusters, simply beautiful, It’s one of my favorites and very easy to find (the link has a finders chart).
This image is Chandra’s latest view of the Perseus Cluster, where red, green, and blue show low, medium, and high-energy X-rays respectively. It combines data equivalent to more than 17 days worth of observing time taken over a decade with Chandra. The Perseus Cluster is one of the most massive objects in the Universe, and contains thousands of galaxies immersed in an enormous cloud of superheated gas.
In Chandra’s X-ray image, enormous bright loops, ripples, and jet-like streaks throughout the cluster can be seen. The dark blue filaments in the center are likely due to a galaxy that has been torn apart and is falling into NGC 1275 (a.k.a. Perseus A), the giant galaxy that lies at the center of the cluster. A different view of Perseus combines data from Chandra in the inner regions of the cluster and XMM data in the outer regions.
NGC 3081 is about 34.3 Mpc away (that’s about 112 Million light-years!) in the constellation of Hydra. There are two People credited with the discovery of this galaxy: by William Herschel on 21 Dec 1786 and later listed as NGC 3081, and by Lewis Swift on 11 Apr 1898 and later listed as IC 2529. The internet was slower back then. Just kidding, it’s not at all far fetched to have independent discoveries.
NGC and IC are both catalogs. IC is for the Index Catalogue of Nebulae and Clusters of Stars which is an update to the New General Catalogue. NGC was put together in the 1880’s by John Dreyer using data from William and John Herschel (father and son). The Index Catalogue or IC was published in two sections by Dreyer in 1895 and 1908.
I think there are at around 7840 entries in the NGC.
Taking center stage in this new NASA/ESA Hubble Space Telescope image is a galaxy known as NGC 3081, set against an assortment of glittering galaxies in the distance. Located in the constellation of Hydra (The Sea Serpent), NGC 3081 is located over 86 million light-years from us. It is known as a type II Seyfert galaxy, characterized by its dazzling nucleus.
NGC 3081 is seen here nearly face-on. Compared to other spiral galaxies, it looks a little different. The galaxy’s barred spiral center is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation, and frames the supermassive black hole thought to be lurking within NGC 3081 — which glows brightly as it hungrily gobbles up in-falling material. Continue reading →