Tight and bright

Esahubble_potw1215a_1024

esahubble_potw1215a April 9th, 2012

Credit: ESA/Hubble & NASA

In this image, the NASA/ESA Hubble Space Telescope has captured the brilliance of the compact centre of Messier 70, a globular cluster. Quarters are always tight in globular clusters, where the mutual hold of gravity binds together hundreds of thousands of stars in a small region of space. Having this many shining stars piled on top of one another from our perspective makes globular clusters a popular target for amateur skywatchers and scientists alike. Messier 70 offers a special case because it has undergone what is known as a core collapse. In these clusters, even more stars squeeze into the object's core than on average, such that the brightness of the cluster increases steadily towards its centre. The legions of stars in a globular cluster orbit about a shared centre of gravity. Some stars maintain relatively circular orbits, while others loop out into the cluster's fringes. As the stars interact with each other over time, lighter stars tend to pick up speed and migrate out toward the cluster's edges, while the heavier stars slow and congregate in orbits toward the centre. This huddling effect produces the denser, brighter centres characteristic of core-collapsed clusters. About a fifth of the more than 150 globular clusters in the Milky Way have undergone a core collapse. Although many globular clusters call the galaxy's edges home, Messier 70 orbits close to the Milky Way's centre, around 30 000 light-years away from the Solar System. It is remarkable that Messier 70 has held together so well, given the strong gravitational pull of the Milky Way's hub. Messier 70 is only about 68 light-years in diameter and can be seen, albeit very faintly, with binoculars in dark skies in the constellation of Sagittarius (The Archer). French astronomer Charles Messier documented the object in 1780 as the seventieth entry in his famous astronomical catalogue. This picture was obtained with the Wide Field Camera of Hubbles Advanced Camera for Surveys. The field of view is around 3.3 by 3.3 arcminutes.

Provider: Hubble Space Telescope | ESA

Image Source: https://www.spacetelescope.org/images/potw1215a/

Curator: ESA/Hubble, Garching bei München, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
M 70
Subject - Milky Way
Star > Grouping > Cluster > Globular
Esahubble_potw1215a_128
 

Position Details

Position (ICRS)
RA = 18h 43m 12.6s
DEC = -32° 17’ 28.4”
Orientation
North is 83.6° CCW
Field of View
3.4 x 3.4 arcminutes
Constellation
Sagittarius

Color Mapping

  Telescope Spectral Band Wavelength
Blue Hubble (ACS) Optical (V) -
Green Hubble (ACS) Optical (Pseudogreen (V+I)) -
Red Hubble (ACS) Infrared (I) -
Esahubble_potw1215a_1280
×
ID
potw1215a
Subject Category
B.3.6.4.2  
Subject Name
M 70
Credits
ESA/Hubble & NASA
Release Date
2012-04-09T10:00:00
Lightyears
Redshift
Reference Url
https://www.spacetelescope.org/images/potw1215a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
ACS, ACS, ACS
Color Assignment
Blue, Green, Red
Band
Optical, Optical, Infrared
Bandpass
V, Pseudogreen (V+I), I
Central Wavelength
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
280.802580441, -32.2912165105
Reference Dimension
4038.0, 4109.0
Reference Pixel
2019.0, 2054.0
Scale
-1.38995522025e-05, 1.38995522025e-05
Rotation
83.579999999999927
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
ESA/Hubble
URL
http://www.spacetelescope.org/
Name
Email
Telephone
Address
Karl-Schwarzschild-Strasse 2
City
Garching bei München
State/Province
Postal Code
D-85748
Country
Germany
Rights
Creative Commons Attribution 4.0 International License
Publisher
ESA/Hubble
Publisher ID
esahubble
Resource ID
potw1215a
Metadata Date
2012-04-03T14:28:49+02:00
Metadata Version
1.1
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Detailed color mapping information coming soon...

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There is no distance meta data in this image.

 

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