WIYN Observatory

NN-Explore Time with NEID

Detailed Description

The NN-explore Exoplanet Investigations with Doppler spectroscopy, or NEID (NUH-eed or NOO-id, rhymes with "fluid"), gets its name from the Tohono O'odham word meaning "to see", is funded by the joint NASA/NSF Exoplanet Exploration Program (or NN-EXPLORE), and is currently being commissioned at WIYN.

Programs using NEID will be scheduled in queue mode with WIYN staff executing the observations. The NASA Exoplanet Science Institute (NExScI) runs the data reduction pipeline and provides high-level data products including extremely precise barycentric-corrected radial velocities via the NEID data archive. We anticipate up to 30 nights of NEID time to be scheduled in 2022A. The port adaptor (built at the University of Wisconsin, Washburn Labs) is mounted on the Bent Cassegrain port at WIYN. It is used to acquire and guide on a target star, precisely maintaining the stellar centroid on a science fiber in the focal plane. Other nearby fibers gather simultaneous light from the sky. Calibration light can also be sent to NEID via the port adaptor. The fibers feed light to NEID, situated in a new spectrograph room built by WIYN on the ground floor of the observatory. The room ensures a stable environment for the spectrograph. The NEID spectrograph is built by Penn State University (Suvrath Mahadevan, PI). It is sealed in a vacuum chamber to maintain the optics at a stable temperature (variations <1 mK) and isolated from outside disturbances over the 5-year program baseline.

Spectrograph Characteristics

System characteristics

Data Products

All data taken with NEID will be processed through the NEID data reduction pipeline run daily at NExScI. The following data products will be available via the NEID archive at NExScI:

The metadata (source, observation time, exposure time, release date) for all observations will be available as soon as the data are ingested in the NEID archive. The data products will be available after a proprietary period, the GO proprietary period is 18 months.

NEID obtains a standard calibration sequence every night and morning, which includes bias, flats and wavelength calibrators. Spectrophotometric and telluric standards will not be taken as standard products; proposers should request these (and account for them in their time request) if they are desired.

NEID also observes a small set of RV standard stars every night, and the raw and reduced data products will be available to the community with zero proprietary period. From the following standard star list, 1-3 will be observed every night NEID operates.

Standard star list:

Queue Policies

NN-EXPLORE time is awarded to a successful proposal in hours in one or more "priority" levels. There are 5 priority levels, each consisting of a certain percentage of the total NN-EXPLORE time for the semester: Priority 0 (8%), Priority 1 (17%), Priority 2 (25%), Priority 3 (25%) and Priority 4 (50%). More information on selecting priorities can be found here:


How to Propose

NEID observations can address a variety of problems. The high radial-velocity precision planned for NEID is its most unique aspect, but NEID proposals are reviewed with the same guidance as NN-EXPLORE proposals to use other instruments at WIYN.

Because of queue scheduling, proposers should consider that observations are taken under a wide variety of conditions and consider the option of proposing projects that can take advantage of relatively poor seeing, transparency or sky brightness. It is likely that competition for observing time will be lessened under such conditions and projects planned with this in mind could be among the most successful. The high efficiency (HE) spectral resolution mode may be useful for certain programs expecting to acquire data under suboptimal conditions.  Upon receiving proposals for the NEID queue, NOIRLab staff will inspect the proposals for technical feasibility.  This information will be passed to the TAC so that the telescope time can be allocated efficiently.

During Phase 2 and 3, proposers will specify the limiting, poorest conditions under which their observations can be taken and will be able to specify relaxed constraints for observations that can take advantage of poor conditions.

For instance:

Additional information

Supplemental information on NEID can be found within the slides from the January 2019 AAS splinter session at https://exoplanets.nasa.gov/internal_resources/1101/

Additional questions can be emailed to neid_info@noirlab.edu.

What to Propose

Proposals for NEID queue time are done in 3 phases. The first of these, Phase 1, includes the ordinary NOIRLab proposal process completed by all proposers (due by the proposal deadline in this Call). The second, Phase 2, will be required for all successful proposals and its purpose is to fill in target and observation details to complete the needed information to schedule observations before the semester starts (due in January 22 for 2022A programs). Phase 3 of an observing program describes changes or requests for new targets made during the observing semester.

Instructions for Phase 1 are given here. Instructions for completing the next phases of the proposal process will be provided in the future.

Proposers to use NEID should fill out the standard NOIRLab proposal forms for 2022A. This is one part of Phase 1. In addition to the standard text descriptions, more details are needed during Phase 1 that describe a program’s targets and observation requests.

To account for the overhead, which you must include in the total time you request in your proposal, account for the number of visits to your target (V), the exposure time in seconds (T) and the number of exposures per visit (N) along with the acquisition overhead time of 300s and readout time of 30s.  A formula for the required telescope time is:

Time (sec) = V * (300 + T*N + 30*(N - 1))


A set of frequently asked questions is available below. An additional set of FAQs is hosted on a separate Penn State site by the NEID instrument team. More details on instrument capabilities and operational modes are available there: https://neid.psu.edu/observers-and-proposers-faq/. Note that the FAQs may be updated in the future to include new questions. You may wish to consult the latest FAQs while preparing your proposal.

  1. Who can I contact if I have unanswered questions about NEID and proposals for using NEID?

    You may send email to neid_info@noirlab.edu. Inquiries will be directed to someone who can answer your questions. Additionally, detailed information from the January 2019 AAS splinter session can be found within the NN-Explore NEID pages at https://exoplanets.nasa.gov/internal_resources/1101/

  2. Since NEID will only be scheduled on about 50% of nights at WIYN, can you provide me with a semester schedule so that I can plan my program?

    The WIYN schedule is determined only after lists of approved programs are returned from all telescope shareholders. It will be published as soon as possible Proposers who anticipate needing a restrictive set of nights to complete their programs should provide a list of requested nights with a description justifying the need.

  3. How will a proposal submitted in response to this call be handled if it is intended as the start of a multi-semester NEID observing program at WIYN?

    The importance of long-term observations with NEID is recognized. It is reasonable to envision long-term plans for your NEID science programs. However, NEID proposals are for one semester only and will need to be re-proposed to continue in future semesters. The NEID queue will attempt to make semester boundaries as seamless as possible for renewed programs.

  4. If my program is awarded time, how will I be able to control how my allocated time is used once the observing semester is underway?

    During Phase 3 you may set targets to be active or inactive (ie. eligible to be observed or not), assign a specific priority to an observation from priority levels of time you are awarded, alter exposure times, and change the timing constraints for when your observations may be scheduled. You may request adding new targets during the semester. There is a long lead time before a requested target may be added (nominally 10 days).

Target List

The file should list each target as a row with the target name, RA, Dec and magnitude. Targets should have unique, easily-recognized names. Any targets that are time critical, requiring specific dates, should be indicated here, noting date requirements.

Example target list follows below: Generic TESS exoplanet targets to be identified before Phase 2. Will be observed between 2 and 10 times each at different phases of a periodic ephemeris with periods ranging from 3 and 21 days. Magnitudes are V.
Priority level 1.

Star10,175, -15.12

Stars requiring one spectrum each at any time.
Magnitudes are all V.
Priority level 3

HD 25082,03 58 48.2,-11 34 42,9.71
HD 33785,05 14 40.6,+42 25 06,8.41
HD 36286,05 30 12.4,-08 37 09,9.42
HD 43685,06 17 36.2,+01 46 30,7.67
HD 47590,06 40 46.9,+33 01 32,7.73
HD 53392,07 04 46.0,-01 49 10,8.49
HD 55922,07 15 15.0,+05 49 06,7.40

Stars requiring a series of spectra during transit to measure
the Rossiter-McLaughlin effect. V-band magnitude.
Priority level 0


Nights requested for Rossiter-McLaughlin observations.

2019-12-16 UT (K2-136c)

GTO (Guaranteed Time Observer) Programs

Time at WIYN used by the NN-EXPLORE Program will be divided into a guaranteed time observer (GTO) program for the Penn State instrument team (16 nights in 2022A) and guest observer (GO) programs from the community submitted through this call.

The primary objective of the NEID GTO survey (https://arxiv.org/abs/2101.11689) is to obtain high-cadence radial velocity (RV) observations of bright, magnetically quiet nearby dwarf stars. The purpose of these observations is to discover low-mass exoplanets that previous surveys lacked the Doppler measurement precision to discover.

80 percent of the NEID instrument team’s GTO allocation (30 queue nights per year total) will be dedicated to this high-cadence survey. The targets of this program will be drawn from the list provided here. Because NEID is not yet commissioned, we cannot be sure at this time which of these stars will be best suited to the GTO survey. As final details of the instrument’s performance become available, the instrument team will revise and reduce this list.

The remaining 20 percent of the GTO allocation will be dedicated to opportunistic RV science, including but not limited to mass measurements of GK dwarfs with V<12 and M dwarfs with V<16 identified by TESS, after the proposal call, to potentially host transiting planets. The GTO team will avoid observing any targets not currently on the GTO list that it knows, prior to the beginning of the semester, are being targeted for similar science by successful NOIRLab GO programs, for instance because they are named in the publicly posted titles or abstracts of successful proposals.


NSF University of Wisconsin Indiana University Purdue University Pennsylvania State University Princeton University

Last modified: 15-Feb-2022 17:42:10 MST