Compass and Scale Image of M31 PHAT+PHAST Mosaic

The Andromeda galaxy, a spiral galaxy, spreads across the width. It is tilted nearly edge-on to our line of sight so that it appears as an extreme oval on its side. The borders of the galaxy are jagged because the image is a mosaic of smaller, square images. The outer edges are blue, while the inner two-thirds are yellowish with a bright, central core. Dark, dusty filamentary clouds wrap around the outer half of the galaxy’s disk. At 10 o'clock, a smaller dwarf elliptical galaxy forms a fuzzy, yellow blob. Hubble's sharp vision distinguishes about 200 million stars within the image. The background of space is black. There are what appears to be steps toward the bottom, mainly toward the middle, which indicates where no data were taken. Interesting regions include: (a) Clusters of bright blue stars embedded within the galaxy, background galaxies seen much farther away, and photo-bombing by a couple bright foreground stars that are actually inside our Milky Way; (b) NGC 206 the most conspicuous star cloud in Andromeda containing a concentration of bright blue stars; (c) A young cluster of blue newborn stars; (d) The satellite galaxy M32, that may be the residual core of a galaxy that once collided with Andromeda. The central core is a yellowish blob of unresolved stars; (e) Dark dust lanes across myriad yellow stars.
About This Image
Caption
This is the largest photomosaic ever made by the Hubble Space Telescope. The target is the vast Andromeda galaxy that is only 2.5 million light-years from Earth, making it the nearest galaxy to our own Milky Way. Andromeda is seen almost edge-on, tilted by 77 degrees relative to Earth’s view. The galaxy is so large that the mosaic is assembled from approximately 600 separate overlapping fields of view taken over 10 years of Hubble observing—a challenge to stitch together over such a large area. The mosaic image is made up of at least 2.5 billion pixels. Hubble resolves an estimated 200 million stars that are hotter than our Sun, but still a fraction of the galaxy’s total estimated stellar population.
Interesting regions include: (a) Clusters of bright blue stars embedded within the galaxy, background galaxies seen much farther away, and photo-bombing by a couple bright foreground stars that are actually inside our Milky Way; (b) NGC 206 the most conspicuous star cloud in Andromeda; (c) A young cluster of blue newborn stars; (d) The satellite galaxy M32, that may be the residual core of a galaxy that once collided with Andromeda; (e) Dark dust lanes across myriad stars.
About The Object
- Object Name
- M31, Andromeda Galaxy, NGC 224
- Object Description
- Spiral Galaxy
- R.A. Position
- 00:42
- Dec. Position
- +41:15
- Constellation
- Andromeda
- Distance
- 2.5 million light-years
About The Data
- Instrument
- ACS
- Filters
- F475W, F814W
About The Image
- Color Info
- This image is a composite of separate exposures acquired by the ACS instrument on the Hubble Space Telescope. Several filters were used to sample broad wavelength ranges. 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) Yellow: F814W (I)
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.
About The Data
- Instrument
- The science instrument used to produce the data.
- Filters
- The camera filters that were used in the science observations.
About The Image
- Color Info
- A brief description of the methods used to convert telescope data into the color image being presented.
Pre-footer
Inbox Astronomy
Sign up to receive the latest news, images, and discoveries about the universe:
Contact our News Team
Ask the News Team
Contact our Outreach Office
Ask the Outreach Office