This striking NASA Hubble Space Telescope image, which shows what looks like the profile of a celestial bird, belies the fact that close encounters between galaxies are a messy business.
This interacting galaxy duo is collectively called Arp 142. The pair contains the disturbed, star-forming spiral galaxy NGC 2936, along with its elliptical companion, NGC 2937 at lower left.
Once part of a flat, spiral disk, the orbits of the galaxy's stars have become scrambled due to gravitational tidal interactions with the other galaxy. This warps the galaxy's orderly spiral, and interstellar gas is strewn out into giant tails like stretched taffy.
Gas and dust drawn from the heart of NGC 2936 becomes compressed during the encounter, which in turn triggers star formation. These bluish knots are visible along the distorted arms that are closest to the companion elliptical. The reddish dust, once within the galaxy, has been thrown out of the galaxy's plane and into dark veins that are silhouetted against the bright starlight from what is left of the nucleus and disk.
The companion elliptical, NGC 2937, is a puffball of stars with little gas or dust present. The stars contained within the galaxy are mostly old, as evidenced by their reddish color. There are no blue stars that would be evidence of recent star formation. While the orbits of this elliptical's stars may be altered by the encounter, it's not apparent that the gravitational pull by its neighboring galaxy is having much of an effect.
Above the pair, an unrelated, lone, bluish galaxy, inconsistently cataloged as UGC 5130, appears to be an elongated irregular or an edge-on spiral. Located 230 million light-years away, this galaxy is much closer to us than the colliding pair, and therefore is not interacting with them. It happens to lie along the same line of sight to foreground Milky Way stars caught in the image.
Arp 142 lies 326 million light-years away in the southern constellation Hydra. It is a member of the Arp catalog of peculiar galaxies observed by astronomer Halton C. Arp in the 1960s.
This color image is a composite of Wide Field Camera 3 photos taken in blue-green, yellow-red, and near-infrared light.
Credits
NASA, ESA, and the Hubble Heritage Team (STScI/AURA)| About The Object | |
|---|---|
| Object Name | Arp 142, NGC 2396/2397 |
| Object Description | Interacting Galaxy Pair |
| R.A. Position | 09h 37m 43.09s |
| Dec. Position | 02° 45' 47.01" |
| Constellation | Hydra |
| Distance | 326 million light-years (100 megaparsecs) |
| About The Data | |
| Data Description | The image was created from Hubble data from proposal : Hubble Heritage Team: PI: Z. Levay, M. Mutchler, L. Frattare, J. Sokol, J. Mack, T. Borders, W. Januszewski, M. Livio, and C. Christian (STScI); and K. Noll (NASA/GSFC). |
| Instrument | HST>WFC3/UVIS |
| Exposure Dates | June 22, 2012 |
| Filters | F475W (g), F606W (V), and F814W (I) |
| About The Image | |
| Color Info | This image is a composite of separate exposures acquired by the WFC3/UVIS instruments. Several filters were used to sample various wavelengths. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: F475W (g) Green: F606W (V) Red: F814W (I) |
| 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. |
