This NASA Hubble Space Telescope image shows three galaxies playing a game of gravitational tug-of-war that may result in the eventual demise of one of them.
Located about 100 million light-years away in the constellation Piscis Austrinus (the Southern Fish), the galaxy interaction may ultimately lead to the three reforming into two larger star cities.
The three galaxies – NGC 7173 (middle left), NGC 7174 (middle right), and NGC 7176 (lower right) – are part of Hickson Compact Group 90, named after astronomer Paul Hickson, who first cataloged these small clusters of galaxies in the 1980s. NGC 7173 and NGC 7176 appear to be smooth, normal elliptical galaxies without much gas and dust.
In stark contrast, NGC 7174 is a mangled spiral galaxy that appears as though it is being ripped apart by its close neighbors. The galaxies are experiencing a strong gravitational interaction, and as a result, a significant number of stars have been ripped away from their home galaxies. These stars are now spread out, forming a tenuous luminous component in the galaxy group.
Ultimately, astronomers believe that NGC 7174 will be shredded and only the two "normal" elliptical galaxies (NGC 7173 and NGC 7176) will remain.
Hubble imaged these galaxies with the Advanced Camera for Surveys in May 2006.
Credits
NASA, ESA, and R. Sharples (University of Durham)| About The Object | |
|---|---|
| Object Name | Hickson Compact Group 90 (HCG 90): NGC 7173, NGC 7174, and NGC 7176 |
| Object Description | Cluster of Interacting Galaxies |
| R.A. Position | 22h 2m 5.61s |
| Dec. Position | -31° 58' 0.44" |
| Constellation | Piscis Austrinus |
| Distance | 106 million light-years (33 megaparsecs) |
| Dimensions | This image is roughly 3.2 arcminutes (1,000,000 light-years or 31,000 parsecs) wide. |
| About The Data | |
| Data Description | This image was created from HST data from proposal : R. Sharples (University of Durham), M. Beasley (University of California, Santa Cruz), J. Blakeslee (Dominion Astrophysical Observatory), S. Zepf and A. Kundu (Michigan State University), and J. Cho (University of Durham). |
| Instrument | HST>ACS/WFC |
| Exposure Dates | May 16, 2006, Exposure Time: 1.2 hours |
| Filters | F850LP (z) and F475W (g) |
| About The Image | |
| Color Info | The image is a composite of separate exposures made by the ACS instrument on the Hubble Space Telescope. Two filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Red: F850LP (z) Green: F850LP (z) + F475W (g) Blue: F475W (g) |
| Compass Image |  |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
