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.

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.

Studying How Galaxy Collisions Affect Star Production

The International Centre for Radio Astronomy Research (ICRAR) is studying the relationship between colliding galaxies and star formation.

Looking beyond the common belief, that star production is faster when two galaxies collide, scientists at ICRAR believe that this is only true if the two galaxies are of similar mass. They theorize that if one galaxy is more massive than the other, the smaller of the galaxies generate less stars while the other has an increase production of it.

They explain that the reason for the unequal production of stars from two galaxies of different mass is because the bigger galaxy strips away its smaller galaxy's gas from its gas clouds which is a primary component for star production.

Hidden Objects Along Center of Milky Way Detected Through Infrared

The VVV survey (VISTA Variables in the Via Lactea) of the VISTA telescope at ESO’s Paranal Observatory in Chile has allowed astronomers to see the central parts of the Milky Way as never before.

Using infrared light, the VVV imaged the Trifid Nebula and revealed that the gas cloud has been hiding two Cepheid variable stars directly behind it but at a far distance.

The pair of cepheid stars hidden by the Trifid Nebula is estimated to be around 37,000 light years away from Earth while the Trifid Nebula is at 5,200 light years away. Cepheid variables are unstable bright stars that brightens and fades over time, in this case, a period of 11 days.

These two stars are the only two known Cepheid variables that are close to the central plane of the Milky Way which is 27,000 light years away from Earth.

The Vista Variables in the Via Lactea is an astronomical survey to map the Milky Way, it's bulge and the disk area close to the center of the galaxy. The VVV survey previously assisted astronomers in constructing a three dimensional map of the Milky Way

Astronomers Construct 3D Image of the Milky Way Galaxy

Using the VVV near-infrared survey from the VISTA telescope at ESO’s Paranal Observatory in Chile and the MPG/ESO 2.2-metre telescope, two separate groups of astronomers have constructed a three dimensional map of the inner regions of the Milky Way Galaxy.

The Milky Way Galaxy is the galaxy where the Earth and the Solar System is located. It is about 100,000 to 120,000 light-years in diameter and may may contain between 100 to 400 billion stars.

The Solar System can be found on the inner edge of the Orion-Cygnus Arm which is about 27,000 light years from the center of the galaxy.The center of the Milky Way is believed to be a supermassive black hole created by the Sagittarius A star when it went supernova.

In late 2012, astronomers using the Visible and Infrared Survey Telescope for Astronomy (VISTA) took a nine gigapixel image of the galaxy center and have used this to catalog more than 84 million stars within.

Eclipsing Binary Star System Accurately Determine Distance To The LMC

Astronomers at the European Southern Observatory have accurately determined the distance of one of the closest galaxies, The Large Magellanic Cloud, to the Milky Way to be 163,000 light-years.

A binary star system, as the name suggests is composed of two stars. These stars orbit around a common center of mass. The brightest of the two stars is called the primary star while the other is the secondary or companion star.

One of the closest galaxies to the Milky Way is the Large Magellanic Cloud (LMC). Astronomers at the European Southern Observatory searched through its 35 million stars to find a binary star system that would help to accurately determine the distance of the LMC to the Milky Way.

The stars found by ESO are known as Cepheid Variables. These are bright but unstable stars that pulsate and vary in brightness (see embedded video below). The star that pulsates more quickly are fainter than the those that pulsates more slowly. As the stars revolve, they eclipse each other and the observed brightness changes as this happens.

The exact light variations depend on the relative sizes of the stars, their temperatures and colors and the details of the orbit while the colors are measured by the comparing the brightness of the stars at various near-infrared wavelengths (the farther an object is, the closer it is to the infra-red wavelength).

By studying the relationship between the duration and its luminosity (period-luminosity relationship) of the Cepheids found at the Large Magellanic Cloud, astronomers can accurately determine its distance to the Milky Way.

The Large Magellanic Cloud is an irregular galaxy that is believed to be once a spiral galaxy but was pulled out of shape because of the gravitational effect of the Milky Way.

Eclipsing Binary Star System

Vista Captures 9 Gigapixel Image of the Center Of The Milky Way Galaxy

The Visible and Infrared Survey Telescope for Astronomy (VISTA) captured a nine gigapixel image of the center of the Milky Way Galaxy. Astronomers have used this image to catalog more than 84 million stars within it.

Because of the high resolution of the image (108,200 by 81,500 pixel), if printed in regular resolution as that of a book, the image would be 9 meters wide by 7 meters tall. This is one of the biggest astronomical images ever produced.

VISTA gigapixel mosaic of the central parts of the Milky Way

“By observing in detail the myriads of stars surrounding the centre of the Milky Way we can learn a lot more about the formation and evolution of not only our galaxy, but also spiral galaxies in general,” explains Roberto Saito (Pontificia Universidad Católica de Chile, Universidad de Valparaíso and The Milky Way Millennium Nucleus, Chile), lead author of the study.