To 2MASS Home The Two Micron All Sky Survey at IPAC

About 2MASS Documentation Publications Data Access Image Gallery Outreach Links to Other Surveys and Databases Search 2MASS Password Protected

2MASS All-Sky Data Release

Anomalies in the Compressed Atlas Images

Below are examples of the types of anomalies found in the Atlas Images.

Click on the thumbnail to see the full Image at each band and the three-color JHKs composite.

REFLECTION/PERSISTENCE GHOST IMAGES OF BRIGHT STARS:

JH Ks3-color
night 000301s scan 070 Image 233
Dichroic reflections (glints) immediately adjacent to
and latent images (persistence) trailing from the star Wolf 359

JH Ks3-color
night 990417s scan 092 Image 115
Reflection artifacts and diffraction spikes in the immediate vicinity of Antares

JH Ks3-color
night 980704s scan 034 Image 162
Striped reflection artifacts and diffraction spikes slightly further away from Antares

JH Ks3-color
night 981029s scan 022 Image 174
More distant reflections ("Christmas tree" artifacts), generally seen at H and Ks only.
This example is Ks only, resulting from R Doradus

JH Ks3-color
night 990318n scan 131 Image 056
Widely separated vertical diffraction spikes degrees away from alpha Herculis

JH Ks3-color
night 980704s scan 039 Image 115
Horizontal diffraction spikes four scans away from Antares

METEOR AND SATELLITE TRAILS:

JH Ks3-color
night 000404s scan 068 Image 209
Nearly east-west meteor/satellite streak is broken into multiple small pieces

JH Ks3-color
night 990810s scan 106 Image 021
A bolide that left both a persistence trail and a curving vapor trail,
even after the frame containing the meteor itself was totally blanked

INSECT TRAILS FROM BUGS ON DEWAR WINDOW:

JH Ks3-color
night 980710n scan 036 Image 021
Bug leaves very bright Ks residuals and holes across J and H Images

JH Ks3-color
night 990622n scan 015 Image 173
Another bug artifact which looks much more like a real astrophysical object,
in this case, a Ks-only nebula.

GLINTS FROM THE EDGE OF CHIP:

JH Ks3-color
night 981228s scan 070 Image 056
A Ks "hat" artifact north of a bright star, a peculiarity or "feature" of the southern data

SPATIAL/TEMPORAL VARIATIONS FROM EXTREME AIRGLOW:

JH Ks3-color
night 980518s scan 066 Image 080
Obvious background changes across H Image

ELECTRONICS ARTIFACTS:

JH Ks3-color
night 000806s scan 142 Image 186
"Line-128" artifact (horizontal line) and tiny "smoke ring",
in this case, seen most prominently at J,
immediately associated with the star tau Ceti

UNCLEANED COSMIC RAYS:

JH Ks3-color
night 000227s scan 049 Image 209
H-only residual cosmic ray

Back to the Atlas/Quicklook Images: Cautionary Notes page.

Back to the All-Sky Data Release page.

Last update: 2002 Sep 18 by J.D. Kirkpatrick

Return to the 2MASS Home Page