The SOHO Extreme ultraviolet Imaging Telescope

brought to you by

The EIT Consortium

EIT data analysis proposal form

A Web form (for those with Web viewers that support forms) can be used to submit a proposal to analyze EIT data. Please note, however, that there are some restrictions on proposals prior to 1996 September 15.

[New] EIT observing plan for tomorrow

The SOHO observing plan for tomorrow includes EIT subfield target coordinates and areas, image times and wavelengths, and formal observing campaigns.

EIT science topics

At its 1996 March meeting, the EIT Consortium decided to list some initial research topics as well as volunteers from the consortium to lead the initial efforts in each area. These are not meant to be exclusive or to indicate permanent rights of any sort, but it would benefit any prospective Guest Investigator (official or otherwise) to contact one of the Consortium members whose names are associated with a topic of interest to the Guest Investigator. The list can be thought of as the initial framework for the EIT Bulletin Board of proposed research.

The science topics list can be found here.

Current solar images from EIT

The image on the left was obtained in the Fe XII emission line at 195 Å, while that on the right was obtained in He II 304 Å. Fe XII (eleven-times ionized Fe) is common at temperatures of 1.5 million K; He II is formed primarily at 60,000 - 80,000 K.

The times at which these images were obtained are available on the SDAC "current solar images" page.

While the pixel scale of the EIT instrument is 1024 x 1024 2.6-arc second pixels, the images to which these thumbnails are linked has been reduced to 512 x 512 to keep the file size reasonable (160 - 200 Kbyte).

New:The LASCO/EIT interim synoptic observing program

The LASCO/EIT synoptic oberving program to be run for ~ 2 months starting on 1996 May 14 describes the C1, C2, C3 and EIT "time slots" in the daily plan. As can be seen from inspection of the plan, very little time is available for EIT high-cadence observations.

EIT data rights policy

The EIT Consortium has released its data rights policy to clarify when and how access to EIT data will be available to non-Consortium members.

What EIT is designed to do

The SOHO EIT is able to image the solar transition region and inner corona in four, selected bandpasses in the extreme ultraviolet (EUV): Using either full-disk or subfield images, the EIT can image active regions, filaments and prominences, coronal holes, coronal "bright points," polar plumes, and a variety of other solar features. The instrument was designed to be used in conjunction with other SOHO instruments, particularly the LASCO visible-light coronagraphs and the SUMER and CDS imaging spectrographs, as well as with ground-based instruments.

The instrument

The EIT is a normal-incidence, multilayer telescope of novel design.

A paper describing the instrument (Delaboudinière et al. 1996, Solar Physics 162, 291) is available in dvi, PostScript, or Adobe pdf form.

Access to full-resolution EIT images

EIT Consortium members can access full-resolution, GIF images in all four wavelengths here.

Response: updated daily

The mean counts per unit time in full-field EIT images in each of the four sectors are plotted from the beginning of operations. Note that 304 Å appears to show the greatest change with time, and with bakeout.

Bakeouts so far: 1996 May 23 - 25, 1996 June 23 - 24.

After the second bakeout, the 304 Å signal appears to be very similar to the signal after the first bakeout. Given the shorter duration of the second bakeout (~ 24 hours vs. ~ 48), this may be considered evidence to support the model that we are seeing the effects of water ice condensing on the detector.

Plots are available for:

Fe IX/X 171 Å Linear Log-linear
Fe XII 195 Å Linear Log-linear
Fe XV 284 Å Linear Log-linear
He II 304 Å Linear Log-linear

Engineering: EIT temperature plots

The most recent plots of:

Data rights policy

At the 1996 March meeting of the EIT Consortium, the Consortium members agreed on a data rights policy to encourage the "widest possible access to and analysis of the EIT data consonant with the rights of the team members whose dedication and expertise made the instrument a reality."

EIT science planning schedule

EIT science planners serve for four weeks (plus a few days). We have a tentative schedule for the next several months.

The EIT Operations Team at NASA Goddard Space Flight Center

Send mail to:

The SDAC home page

The SOHO home page

Web curator: Joseph B. Gurman
Responsible NASA official: Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center
+1 301 286-4767

NASA Goddard Space Flight Center
Solar Physics Branch / Code 682
Greenbelt, MD 20771

Last revised - J.B. Gurman