How to prepare observations for EIS?



We are delighted to announce that Hinode (formerly Solar-B, and prounounced "hee-no-day", meaning "Sunrise") was successfully launched from the Uchinoura Space Centre (USC) in southern Japan at
22:36 BST on Friday 22nd September, on the last of JAXA's Mu-V rockets. This was a dawn launch in Japan, which helped put the spacecraft into its Sun-synchronous, 90-minute orbit around the Earth. All signs so far from the spacecraft are good, so to coincide with the launch of Hinode, we would like to take this opportunity to invite proposals from the UK community for observations with Hinode's EUV Imaging Spectrometer (EIS).

Instrument Background

Hinode/EIS is a two-channel, normal-incidence EUV spectrometer. Its two channels cover the ranges
170-210 Å and 250-290 Å, and are designed to observe solar coronal emission lines. The scientific purpose of EIS is to study the response of the corona to changes observed by Hinode's Solar Optical Telescope (SOT) with its vector magnetograph and to compare observations with the full Sun-imaging X-Ray Telescope (XRT), also on-board.

EIS has a mirror which is tiltable in the Solar X direction, and is used to build up rastered spectral
images of the Sun in up to 25 spectral ranges. Additionally, EIS has both narrow (one- and two- arcsecond wide) slits, and wider (40- and 266-arcsecond) imaging slots, all with 512 arcseconds in the cross-dispersion (Solar Y) direction. Under nominal conditions, the 40-arcsecond slot can be used to make simultaneous, separated, quasi-monochromatic images in up to twelve strong emission lines covering a temperature range from He II (log T 4.9) to Fe XXIV (log T 7.2). EIS should be able to make
slit images of active regions in 10 seconds, of quiet Sun in between 30 and 60 seconds, and of flares in approximately one second.

Without moving the coarse mirror pointing, EIS is able to cover a spatial range in Solar X of 360 arcseconds. If the coarse mirror movement is engaged, EIS can off-point (in Solar X) from the centre of XRT's and SOT's pointing by almost one solar radius (890").

Observing With Other Hinode Instruments

To prepare observations for the Solar Optical Telescope or X-Ray Telescope aboard Hinode, please contact the corresponding instrument teams. If you would like to propose tightly coordinated observation programmes between EIS and/or XRT, please notify each team instrument of this so that the appropriate Science Schedule Coordinators (SSCs) will be aware of this when evaluating and scheduling your observations.

Procedure for Submitting Hinode/EIS Proposals

For the first three months of science observations, Hinode will carry out a programme of pre-defined
work, known as the Ninety-Day Plan, designed to achieve certain high priority solar physics scientific goals with this new observatory. Access to these data will be restricted within the first six months of the mission although a subset will be released to the general community over this period. After these first ninety days, observations from the community at large will be run. Therefore we encourage the UK community, which has a major stake in Hinode, to participate in its observation programme, with a particular (although not exclusive) interest in EIS. Observation proposals must be submitted in two
parts, as described below: a formal ASCII study definition; and a plain-text science case.

Study Definition

In order to standardise the proposal submission process for Hinode/EIS, the EIS team has made the observation programme (or "study") definition software (often referred to as the EIS Planning Tool) available through SolarSoft, since this is the most commonly used software package for solar data analysis. Once the EIS branch of SolarSoft has been included in your local distribution, this is run by adding the "eis" branch of SolarSoft to your instrument list in the usual way, e.g., at the command
prompt (in Linux/Unix/OS X Darwin): setssw eis or setting the environment variable $SSW_INSTR to include the string "eis". Note that it is not advisable to include both "eis" and "cds", as some conflicts have been known to arise when both of these branches are included in the SSW path. Then one can
type "eis_mk_raster" in SolarSoft IDL to start the EIS planning tool suite. This is followed by combining rasters (a catch-all term for both spatially scanning rasters and sit-and-stare observations) in eis_mk_study. Attendees of the UK EIS Planning Tutorial at MSSL in June of this year will already be familiar with this process.

Once the study has been defined, it must be exported to ASCII format so that it can be processed by
the submissions system at MSSL. This is done within eis_mk_study, once the study has been fully defined, by selecting "Study, Export..." and saving the file (preferably with a ".def" extension) to a convenient location.

This ASCII .def file must then be included as an attachment to an e-mail, to be sent to It is important that you also include a science case for the observation, or the proposal will be automatically rejected! This information is essential for presenting the proposal at the monthly Hinode scheduling meetings. The format of this proposal is described below.

Science Case

All studies submitted must be accompanied by a science case, which is evaluated by the Science Schedule Co-ordinators (SSCs) for Hinode. (The UK SSC is Prof. J.L. Culhane). Each science case must be in plain English, and consist of no more than 500 words (equivalent to one page of A4, typed
in Times New Roman, at 12pt font size).

In order to evaluate the feasibility of proposed observations, you should include predicted count rates
(per pixel). These can be entered at the end of your proposal in a tab-delimited form as follows
(shown for an active region example) with an indication of the exposure time:

Exposure duration: 10 seconds
Ion SpeciesWavelength (Å)Total Counts for Exposure (per pixel)
Ca XVII192.82572.40
Fe XII195.124240.8
Fe XIII200.02360.00
Fe XIII201.13321.50
He II256.32246.90
Si VII275.35117.60

These tabulated data will not be counted in the 500-word limit. Note that all observations MUST include the three core lines, which are common to all EIS observations (for the purpose of making standard data products). These lines (in Angstroms) are:

Core lines
Ca XVII192.82
Fe XII195.12
He II256.32

Please also include any special requirements, such as:

  • Specific UT time ranges when the observations should be run (e.g. to co-ordinate with ground-based observatories);
  • The kind of target or special conditions desired (e.g. decaying active region, coronal hole at the limb);
  • The type of observation by SOT and/or XRT which would be most useful for the interpretation of your observations;
  • Any other details which may not be readily apparent to the Chief Observer (CO) who will be scheduling the observations.

    The science case MUST be in plain text (no HTML or other formatting) and must form the body of the e-mail. Do not worry about the inclusion of e-mail signatures or other such information, as this will be ignored by the system. However, we do ask that you restrict the number of attachments to just one (i.e. the study- definition file).

    An unsuccessful science case will be returned to the lead author with feedback. Successful proposals will have the corresponding study tested on the EIS Engineering Model at MSSL, which acts as an instrument simulator in order to check for any technical problems with running the observations.

    If the testing stage is passed successfully, the study will be entered into the official EIS study database, and passed on to the monthly Hinode meetings, where observations between the three co-ordinated instruments are discussed and provisionally scheduled. The official EIS database will also be mirrored through SolarSoft so that the general community can be aware of approved and existing observation programmes.

    Summary

    We would ask interested parties to submit a 500-word plain-text science case as the body of an e-mail, and attach the ASCII study-definition file exported from eis_mk_study. Please send this e-mail to

    If you have further queries about this process, please contact the Hinode EIS team at the same e-mail address: and include the word "query" in the subject line.

    We look forward to your successful involvement in Hinode!

    Sincerely,
    The UK Hinode/EIS Team


    Last Revised: Monday, 24-Jul-2008

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