Jump to content

File:Caldwell 17 (50290241446).jpg

Page contents not supported in other languages.
This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Original file (4,198 × 3,881 pixels, file size: 18.14 MB, MIME type: image/jpeg)

Summary

Description

Caldwell 17, also known as NGC 147, is a dwarf galaxy located roughly 2.5 million light-years from Earth. It is a member of the Local Group of galaxies, which is dominated by our Milky Way and the Andromeda galaxy. Caldwell 17, like its neighbor Caldwell 18, is a distant satellite of the Andromeda galaxy. Just as the planets in the solar system are gravitationally bound to the Sun, so are these smaller galaxies bound to their much more massive galactic host. While many classes of galaxies can exist as satellites, dwarf spheroidal galaxies (small, dim, spherical-shaped galaxies) like Caldwell 17 have been observed in this role more frequently than any other type of galaxy.

Dwarf satellite galaxies tend to appear very diffuse and dim, so they can be difficult to spot (especially in light-polluted or hazy skies). Caldwell 17 is no exception. It has an apparent magnitude of 9.5, and observers will need a small telescope set up in a dark location to detect the faint galaxy. Caldwell 17 is located in the southern edge of the constellation Cassiopeia, between the constellation’s “W” pattern and the Andromeda galaxy. (The neighboring Caldwell 18 is brighter and less diffuse, so it is easier to see.) The best time of year to spot Caldwell 17 from the Northern Hemisphere is the autumn. It can also be seen in northern latitudes of the Southern Hemisphere in the spring. The galaxy was discovered by the English astronomer John Herschel in September of 1829.

This image of Caldwell 17 is a composite of observations made in visible and infrared light by Hubble’s Wide Field Camera 3. The image captures an area near the core of the galaxy, which is notable for its elderly stellar population. Astronomers used Hubble’s observations to investigate the properties of Caldwell 17’s many globular star clusters.

Credit: NASA, ESA, and A. Ferguson (University of Edinburgh, Institute for Astronomy); Processing: Gladys Kober (NASA/Catholic University of America)

For Hubble's Caldwell catalog website and information on how to find these objects in the night sky, visit: <a href="https://www.nasa.gov/content/goddard/hubble-s-caldwell-catalog" rel="noreferrer nofollow">www.nasa.gov/content/goddard/hubble-s-caldwell-catalog</a>
Date
Source Caldwell 17
Author NASA Hubble Space Telescope

Licensing

w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 2.0 Generic license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
This image was originally posted to Flickr by NASA Hubble at https://flickr.com/photos/144614754@N02/50290241446. It was reviewed on 16 December 2020 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0.

16 December 2020

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

26 June 2020

image/jpeg

845863d094ec87aceeaf3f4f76c986eaa01f8db1

19,017,462 byte

3,881 pixel

4,198 pixel

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current17:43, 16 December 2020Thumbnail for version as of 17:43, 16 December 20204,198 × 3,881 (18.14 MB)SzczureqTransferred from Flickr via #flickr2commons

The following page uses this file:

Global file usage

The following other wikis use this file:

Metadata