Clean Dwarf Galaxy Help Chart Universe

The image above is of IC 1613, a dwarf galaxy that is found in the Cetus constellation.

IC 1613 is unique in that unlike other galaxies, this dwarf galaxy contains very little cosmic dust which allows a clearer exploration of what is inside it. Cosmic dust is made of various heavier elements, such as carbon and iron, as well as larger, grainier molecules. Not only does dust block out light, making dust-shrouded objects harder to see, it also preferentially scatters bluer light. As a result, cosmic dust makes objects appear redder when seen through telescopes than they are in reality. Astronomers can factor out this reddening when studying objects. Still, the less reddening, the more precise an observation is likely to be.

IC 1613 also contains two types of stars, Cepheid variables and RR Lyrae variables. These type of stars rhythmically pulsate, growing characteristically bigger and brighter at fixed intervals and are used to measure galactic distances.

Galaxies come in different sizes. Our galaxy, The Milky Way, is a regular sized galaxy which contains 200 to 400 billion stars. There are smaller galaxies like the dwarf galaxy which only has several billion stars inside it. Dwarf galaxies like IC 1613, are small and have been observed to be pulled toward and merge with nearby spiral galaxies.

The OmegaCam was used to capture the image above. The OmegaCAM is a 32-CCD, 256-million-pixel camera mounted on the 2.6-metre VLT Survey Telescope at Paranal Observatory in Chile.

ESO Studying Mysterious Dwarf Galaxy Formed After Cosmic Collision

The European Southern Observatory used its Very Large Telescope at the Paranal Observatory to take detailed images of NGC 5291. NGC 5291 is located in the constellation of Centaurus. NGC 5291 is an elliptical galaxy that collided with another galaxy over 360 million years ago.

As a result of the collision, a dwarf galaxy was also formed; NGC 5291N. Astronomers have particular interest with this dwarf galaxy because according to their data, NGC 5291N mysteriously contains no old stars.

Centered in the image above is NGC 5291. Also seen is the Seashell Galaxy (MCG-05-33-005), a comma-shaped galaxy which appears to leech off NGC 5291’s luminous core. On the right side of the image is NGC 5291N. The dwarf galaxy was observed using MUSE's integral field spectrography.

The MUSE observations revealed unexpected oxygen and hydrogen emission lines in the outskirts of NGC 5291N.

A dwarf galaxy is a small galaxy containing less stars than a regular galaxy. It is usually composed of up to several billion stars. A regular galaxy like the Milky Way has 200 to 400 billion stars. Since these dwarf galaxies are small, they have been observed to be pulled toward and merge with nearby spiral galaxies. The Milky Way is believed to be a result of a build up of several dwarf galaxies.

Image of Sculptor Dwarf Galaxy Captured By ESO

The Sculptor Dwarf Galaxy, pictured in this new image from the Wide Field Imager camera, installed on the 2.2-metre MPG/ESO telescope at ESO’s La Silla Observatory, is a close neighbour of our galaxy, the Milky Way. Despite their close proximity, both galaxies have very distinct histories and characters. This galaxy is much smaller and older than the Milky Way, making it a valuable subject for studying both star and galaxy formation in the early Universe. However, due to its faintness, studying this object is no easy task.

The Sculptor Dwarf Galaxy — also known as the Sculptor Dwarf Elliptical or the Sculptor Dwarf Spheroidal — is a dwarf spheroidal galaxy, and is one of the fourteen known satellite galaxies orbiting the Milky Way. This is not to be confused with the similarly named and much brighter Sculptor Galaxy which is located in the same constellation of Sculptor.

A dwarf galaxy is a small galaxy composed of up to several billion stars. A regular galaxy like the Milky Way has 200 to 400 billion stars. Since these dwarf galaxies are small, they have been observed to be pulled toward and merge with nearby spiral galaxies.

Extremely Rare Gravitational Lensed Dwarf Galaxy Imaged By Hubble Space Telescope

This picture from the NASA/ESA Hubble Space Telescope shows the most distant gravitational lens yet discovered. The glow at the centre of this picture is the central regions of a normal galaxy. By chance it is precisely aligned with a much more remote, young star-forming galaxy. The light from the more distant object is bent around the nearer object by its strong graviational pull to form a ring of multiple images. The chance of finding such an exactl alignment is very small, suggesting that there may be more star-forming galaxies in the early Universe than expected.
Credit: NASA/ESA/A. van der Wel

The Hubble Space Telescope as part of the CANDELS and COSMOS survey has captured an extremely rare and very distant dwarf galaxy that is gravitationally lensed. The dwarf galaxy is a record 9.4 billion light years away. It is a young starburst galaxy that forms a perfect Einstein ring, indicating a gravitational lens with very precise alignment of the lens and the background light source.

When two objects (the light source and a lensing mass) is observed, the light from the source is bent and deflected by the gravity of the lensing mass. It allows scientists to measure the mass of the lensing mass as well as the surrounding dark matter (which does not interact with light and only can be detected by gravitational effects).

Similar to looking at an object through a wine glass, the light is bent and forms a circle which is called an Einstein ring. The lens also magnifies the background light source, acting as a "natural telescope" that allows astronomers a more detailed look at distant galaxies than is normally possible.

In the captured image, the formation of the lens is extremely rare as the alignment has a one millimeter separation at a distance of 20 kilometers - a near perfect alignment.