NOTICE: This site is no longer being actively maintained
On October 1, 2019 NOAO joined with Gemini Observatory and Rubin Observatory operations to create a new organization, NSF’s NOIRLab. The content of this site is being migrated to our new domain: The public site has been launched and is the main web portal for the public and media. Many links on this site may redirect you to the new site. For now, scientists and astronomers can still find information about Kitt Peak, CTIO, and CSDC on the old site ( October 28, 2020

NOAO < IMAGE GALLERY < Comet Giacobini-Zinner

Comet Giacobini-Zinner, November 1st 1998

[Comet Giacobini-Zinner]

About this image

Comet Giacobini-Zinner, a fairly frequent visitor to the inner solar system, was captured by the Kitt Peak 0.9-meter telescope on Halloween Night 1998 (UT November 1st, from 02:07 to 03:40). North is up with east to the left.

Since the comet was moving across the sky fairly quickly, and since color images are made by combining successive exposures through three different filters, a conventional combination would have either a streaked comet or a set of colored dots for each star. To avoid this, the complete sequence of images, lasting over ninety minutes, was specially processed. All frames for one color were combined with filtering that removed the moving comet: this stars-only image was subtracted from each comet frame, and the comet frames were registered and summed with further filtering to remove any residuals. The two images, with stars only and with comet only, were then added together to produce a single-color image in which neither the comet nor the stars was trailed. These three frames were then united in the final color picture, shown here.

More: solar system page.

Minimum credit line: N.A.Sharp/NOAO/AURA/NSF

Downloadable versions:
400 x 400 36 kb color JPEG (on this page)
1600 x 1600 456 kb color JPEG
1600 x 1600 2.5 Mb 8-bit color TIFF
1600 x 1600 7.5 Mb 24-bit color TIFF
(see NOAO Conditions of Use)

Comments by e-mail to