How to Find a Planetary Hot Spot

Spitzer_ssc2010-08a_1024

spitzer_ssc2010-08a October 19th, 2010

Credit: NASA/JPL-Caltech/UCLA

This graph of data from NASA's Spitzer Space Telescope shows how astronomers located a hot spot on a distant gas planet named upsilon Andromedae b -- and learned that it was in the wrong place.

This planet -- termed an exoplanet because it orbits a star beyond our sun -- whips around very closely to its star. It is tidally locked, meaning that one side always faces the star. One might think the hottest point of the planet would be smack dab in the middle of this sun-facing side, but previous research has shown that exoplanet hot spots can be offset, or over to the side, by up to 30 degrees.

This plot shows that the hot spot on upsilon Andromedae b is even farther over to the side -- a whopping 80 degrees. Astronomers figured this out by measuring the total infrared light of the planet and star, as the planet orbits around. (The planet is not transiting or crossing in front of its star, so it doesn't block the star's light.) When the hot spot faces Earth, the total brightness of the system will go up, as measured by Spitzer's heat-seeking, infrared eyes.

The black line shows what the system's light variations, or light curve, would look like if the hot spot were in the middle of the sun-facing side of the planet. The yellow line shows what was actually observed: the light curve is offset by 80 degrees, indicating that the hot spot is, oddly, almost all the way over the side. Astronomers are not sure how this can be.

Provider: Spitzer Space Telescope

Image Source: http://www.spitzer.caltech.edu/images/3407-ssc2010-08a-How-to-Find-a-Planetary-Hot-Spot

Curator: Spitzer Space Telescope, Pasadena, CA, USA

Image Use Policy: Public Domain

View Options

Image Details

Image Type
Chart
Object Name
Upsilon Andromedae b
Subject - Milky Way
Planet > Type > Gas Giant
Planet > Special Cases > Hot Jupiter

Distance

Universescale1
44 light years

Position Details

Position (ICRS)
RA = 1h 36m 47.8s
DEC = 41° 24’ 19.7”
Constellation
Andromeda

Color Mapping

  Telescope Spectral Band Wavelength
Spitzer (MIPS) Infrared (Mid-IR) 24.0 µm
Chart is a time sequence observed at 24 microns
Spectrum_ir1
Spitzer_ssc2010-08a_1280
×
ID
ssc2010-08a
Subject Category
B.1.1.2.   B.1.3.2.  
Subject Name
Upsilon Andromedae b
Credits
NASA/JPL-Caltech/UCLA
Release Date
2010-10-19
Lightyears
44
Redshift
44
Reference Url
http://www.spitzer.caltech.edu/images/3407-ssc2010-08a-How-to-Find-a-Planetary-Hot-Spot
Type
Chart
Image Quality
Good
Distance Notes
Facility
Spitzer
Instrument
MIPS
Color Assignment
Band
Infrared
Bandpass
Mid-IR
Central Wavelength
24000
Start Time
Integration Time
Dataset ID
Notes
C
Coordinate Frame
ICRS
Equinox
Reference Value
24.19933333, 41.40547222
Reference Dimension
Reference Pixel
Scale
Rotation
Coordinate System Projection:
Quality
Position
FITS Header
Notes
Creator (Curator)
Spitzer Space Telescope
URL
http://www.spitzer.caltech.edu
Name
Email
Telephone
Address
1200 E. California Blvd.
City
Pasadena
State/Province
CA
Postal Code
91125
Country
USA
Rights
Public Domain
Publisher
Spitzer Science Center
Publisher ID
spitzer
Resource ID
ssc2010-08a.tif
Metadata Date
2011-09-01
Metadata Version
1.1
×

 

Detailed color mapping information coming soon...

×
Universescalefull
44 light years

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