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Collection:
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NASA Scientific Visualization Studio Collection
Collection
NASA Scientific Visualization Studio Collection
Collection
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Title:
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The Tycho Catalog Skymap
Title
The Tycho Catalog Skymap
Title
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Description:
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These are high-resolution versions of the skymaps. They are best suited for use when you need a small field-of-view and don't want bright stars to overpower the image.
Description
These are high-resolution versions of the skymaps. They are best suited for use when you need a small field-of-view and don't want bright stars to overpower the image.
Description
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Abstract:
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This image set is a skymap of stars from the Tycho and Hipparcos star catalogs.
The maps are plotted in Platte-Carre projection (Cylindrical-Equidis tant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible.
Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels.
About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds.
[The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.]
Abstract
This image set is a skymap of stars from the Tycho and Hipparcos star catalogs.
The maps are plotted in Platte-Carre projection (Cylindrical-Equidis tant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible.
Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels.
About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds.
[The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.]
Abstract
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Completed:
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2007-08-14
Completed
2007-08-14
Completed
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Credit:
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*Please give credit for this visualization to*
NASA/Goddard Space Flight Center Scientific Visualization Studio
Credit
*Please give credit for this visualization to*
NASA/Goddard Space Flight Center Scientific Visualization Studio
Credit
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Studio:
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SVS
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Animator:
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Tom Bridgman (Lead)
Animator
Tom Bridgman (Lead)
Animator
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Data Collected:
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November 1989 - March 1993
Data_Collected
November 1989 - March 1993
Data Collected
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Keywords:
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SVS
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Keywords:
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HDTV
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Keywords:
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Sky Map
Keywords
Sky Map
Keywords
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Keywords:
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Milky Way
Keywords
Milky Way
Keywords
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Keywords:
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Stars
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facet_where:
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Andromeda Galaxy
facet_where
Andromeda Galaxy
facet_where
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facet_where:
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M31
facet_where
M31
facet_where
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facet_where:
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Goddard Space Flight Center (GSFC)
facet_where
Goddard Space Flight Center (GSFC)
facet_where
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facet_when:
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August 28, 2007
facet_when
August 28, 2007
facet_when
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facet_when:
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November 1989
facet_when
November 1989
facet_when
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facet_when:
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March 1993
facet_when
March 1993
facet_when
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facet_what:
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Polar
facet_what
Polar
facet_what
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facet_what:
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Andromeda
facet_what
Andromeda
facet_what
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facet_what:
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ESO
facet_what
ESO
facet_what
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facet_what:
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Hipparcos
facet_what
Hipparcos
facet_what
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facet_when_year:
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1993
facet_when_year
1993
facet_when_year
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facet_when_year:
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1989
facet_when_year
1989
facet_when_year
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facet_when_year:
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2007
facet_when_year
2007
facet_when_year
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Animation Number:
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3442
Animation_Number
3442
Animation Number
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UID:
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SPD-SCIVS-http://svs .gsfc.nasa.gov/vis/a 000000/a003400/a0034 42/TychoSkymap-IMAGE
UID
SPD-SCIVS-http://svs .gsfc.nasa.gov/vis/a 000000/a003400/a0034 42/TychoSkymap-IMAGE
UID
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original url:
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original_url
original url
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