Speed Demon Creates a Shock

Wise_wise2011-010_1024

wise_WISE2011-010 March 10th, 2011

Credit: NASA/JPL-Caltech/UCLA

Just as some drivers obey the speed limit while others treat every road as if it were the autobahn, some stars move through space faster than others. NASAs Wide-field Infrared Survey Explorer, or WISE, captured this image of the star Alpha Camelopardalis, or Alpha Cam in astronomer-speak, speeding through the sky like a motorcyclist zipping through rush-hour traffic. The supergiant star Alpha Cam is the bright star in the middle of this image, surrounded on one side by an arc-shaped cloud of dust and gas, colored red in this infrared view.

Such fast-moving stars are called runaway stars. The distance and speed of Alpha Cam is somewhat uncertain. It is probably somewhere between 1,600 and 6,900 light-years away and moving at an astonishing rate of somewhere between 680 and 4,200 kilometers per second (between 1.5 and 9.4 million miles per hour). It turns out that WISE is particularly adept at imaging bow shocks from runaway stars. Previous examples can be seen around zeta Ophiuchi , AE Aurigae, and Menkhib. But Alpha Cam cranks things up into a different gear. To put its speed into perspective, if Alpha Cam were a car driving across the United States at 4,200 kilometers per second, it would take less than one second to travel from San Francisco to New York City!

Astronomers believe runaway stars are set into motion either through the supernova explosion of a companion star or through gravitational interactions with other stars in a cluster. Because Alpha Cam is a supergiant star, it gives off a very strong wind. The speed of the wind is boosted in the forward direction the star is moving in space. When this fast-moving wind slams into the slower-moving interstellar material, a bow shock is created, similar to the wake in front of the bow of a ship in water. The stellar wind compresses the interstellar gas and dust, causing it to heat up and glow in infrared. Alpha Cams bow shock cannot be seen in visible light, but WISEs infrared detectors show us the graceful arc of heated gas and dust around the star.

The red arc of Alpha Cam adds to collection of colorful objects in WISE images taken of the constellation Camelopardalis, or the Giraffe. The gaudily clad giraffe has what looks like a ruby choker above an emerald necklace just to the southeast, as well as an ankle bracelet.

The colors used in this image represent specific wavelengths of infrared light. Stars are seen primarily in blue and cyan (blue-green), because they are emitting light brightly at 3.4 and 4.6 microns. Green represents 12-micron light, primarily emitted by dust. The red of the blow shock represents light emitted at 22 microns.

Provider: Wide-field Infrared Survey Explorer

Image Source: /image/wise/WISE2011-010

Curator: Wide-field Infrared Survey Explorer, Berkeley, CA, USA

Image Use Policy: Pulic Domain

Download Options

  • Full Size Image (2700 x 2700)

Image Details

Image Type
Observation
Object Name
Alpha Camelopardalis Alpha Cam
Subject - Milky Way
Star > Spectral Type > O
Nebula > Type > Interstellar Medium

Distance

Universescale1
7,000 light years
Wise_wise2011-010_128
 

Position Details

Position (ICRS)
RA = 4h 54m 14.6s
DEC = 66° 22’ 7.0”
Orientation
North is 90.7° CCW
Field of View
1.0 x 1.0 degrees
Constellation
Camelopardalis

Color Mapping

  Telescope Spectral Band Wavelength
Blue WISE Infrared (Near-IR) 3.4 µm
Cyan WISE Infrared (Near-IR) 4.6 µm
Green WISE Infrared (Mid-IR) 12.0 µm
Red WISE Infrared (Mid-IR) 22.0 µm
Spectrum_ir1
Blue
Cyan
Green
Red
Wise_wise2011-010_1280
×
ID
WISE2011-010
Subject Category
B.3.3.1.   B.4.1.1.  
Subject Name
Alpha Camelopardalis, Alpha Cam
Credits
NASA/JPL-Caltech/UCLA
Release Date
2011-03-10
Lightyears
7,000
Redshift
Reference Url
/image/wise/WISE2011-010
Type
Observation
Image Quality
Good
Distance Notes
Facility
WISE, WISE, WISE, WISE
Instrument
Color Assignment
Blue, Cyan, Green, Red
Band
Infrared, Infrared, Infrared, Infrared
Bandpass
Near-IR, Near-IR, Mid-IR, Mid-IR
Central Wavelength
3400, 4600, 12000, 22000
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
73.5606761, 66.3686201
Reference Dimension
2700.0, 2700.0
Reference Pixel
1351.0, 1351.0
Scale
-3.81944439141100e-04, 3.81944439141100e-04
Rotation
90.7
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
Wide-field Infrared Survey Explorer
URL
http://wise.astro.ucla.edu
Name
Email
outreach@ssl.berkeley.edu
Telephone
Address
7 Gauss Way
City
Berkeley
State/Province
CA
Postal Code
94720
Country
USA
Rights
Pulic Domain
Publisher
Publisher ID
wise
Resource ID
Resource URL
/image/wise/WISE2011-010
Related Resources
Metadata Date
2011-08-05
Metadata Version
1.2
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Detailed color mapping information coming soon...

×
Universescalefull
7,000 light years

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