Wikimedia Commons

File:Comet Hale-Bopp (eso9521c).jpg

Original file ‎(908 × 774 pixels, file size: 176 KB, MIME type: image/jpeg)

Captions

Captions

This image was produced through successive use of photographic enhancement and subtraction, followed by smoothing by computer processing .

Summary

edit
Description
English: This image was produced through successive use of photographic enhancement and subtraction, followed by smoothing by computer processing . When a matching, earlier exposure of the same sky field with the same telescope (on which the comet is not present) is photographically subtracted from the enhanced photo of the same field in which the comet is present, then the images of the stars should in principle cancel out, leaving only that of the comet in the field. A full cancellation is virtually impossible to achieve in practice, but if the resulting image is heavily smoothed (i.e. substituting each image element with the mean intensity of its surroundings), then the smaller images of the stars disappear and the full extent of the comet's large coma becomes visible. This false-colour photo was produced in this way by means of computer processing within the MIDAS image processing system. The images of the brightest stars could not be completely removed by this process and faint remnants are still present. (In technical terms, a 2-D low-pass Fourier filter was used to achieve heavy smoothing over approx. 16 x 16 arcsec cells).
Date 30 August 1995 (upload date)
Source
This media was produced by the European Southern Observatory (ESO), under the identifier eso9521c

This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing.

Author ESO
Other versions
  • TIFF version
    TIFF version

Licensing

edit
This media was created by the European Southern Observatory (ESO).
Their website states: "Unless specifically noted, the images, videos, and music distributed on the public ESO website, along with the texts of press releases, announcements, pictures of the week, blog posts and captions, are licensed under a Creative Commons Attribution 4.0 International License, and may on a non-exclusive basis be reproduced without fee provided the credit is clear and visible."
To the uploader: You must provide a link (URL) to the original file and the authorship information if available.
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current22:51, 14 June 2024Thumbnail for version as of 22:51, 14 June 2024908 × 774 (176 KB)OptimusPrimeBot (talk | contribs)#Spacemedia - Upload of https://www.eso.org/public/archives/images/large/eso9521c.jpg via Commons:Spacemedia

You cannot overwrite this file.

The following page uses this file:

Metadata

This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.

Retrieved from "https://commons.wikimedia.org/w/index.php?title=File:Comet_Hale-Bopp_(eso9521c).jpg&oldid=884108839"