K2 proposal preparation

There are no guaranteed, or predetermined, targets for any of the fields where K2 is pointing. All targets are proposed by the community through the Guest Observer (GO) program. This page details the program and its aims.

Note: owing to the limited amount of spacecraft fuel remaining, current and future K2 GO opportunities are at risk of fuel running out in the course of 2018 or 2019.

Guest Observer program

Permitted science areas

The K2 GO program welcomes proposals addressing compelling scientific questions in any area of astrophysics and planetary science providing the required observations are amenable to the operational characteristics and constraints of the mission. The science motivation may include, but is not limited to, exoplanet detection, stellar astrophysics, galactic and extragalactic astrophysics, and solar system science.

Proposers must take into account the difference between science that can be achieved exclusively using archived K2 and Kepler data and science that requires new observations by K2. The K2 GO program is specific to the case of science requiring new observations (Campaign 20 in the case of K2 GO Cycle 7). Funding for archival science is instead provided through NASA's Astrophysics Data Analysis Program (ADAP). This includes all Kepler data and archived data from K2 Campaigns. All proposals to the K2 GO calls therefore must justify the need for new observational data within their program. However, we welcome proposals that build upon data already collected and programs requiring more data to enhance or complete investigations.

Evaluation criteria

Phase-2 proposals that are submitted via NSPIRES in response the K2 GO Cycle 7 call will be evaluated with respect to the criteria specified in Section C.2 of the NASA Guidebook for Proposers, which are intrinsic merit, relevance to the GO solicitation, and the realism/reasonableness of the proposed work effort and resources. In addition to the factors for intrinsic merit given in the NASA Guidebook for Proposers, intrinsic merit includes the following factors:

  • The suitability of using the K2 observatory and data products for the proposed investigation;
  • The legacy value of the data collected;
  • The degree to which the investigation uses K2’s unique capabilities;
  • The feasibility of accomplishing the objectives of the proposed investigation with the requested observations, including the degree to which the proposal satisfies K2’s observational constraints; and
  • The feasibility and suitability of the proposed analysis techniques.

All Phase-2 proposals are peer-reviewed and ranked by a panel of professional volunteers, followed by ratification from NASA Headquarters. The members of the peer-review panel will not be disclosed. The deliberations of the panel will be disclosed to PIs only after ratification by the selecting official.

Availability of funds

There are typically two categories of K2 GO proposals. They are:

  • Small proposals—proposals using fewer than 1000 targets, with a budget capped at $50,000.
  • Large proposals—proposals using 1000 or more targets, with a budget capped at $150,000. Large proposals must also include the development and dissemination of a value-added community resource product that the proposal will provide at the end of the period of performance of the grant and how that product will be made available to the community.

Funding for selected programs typically starts upon availability of campaign data to the public archive at MAST. Note that there is no exclusive use period associated with any K2 GO data.

In K2 GO Cycle 7, only Phase-2 proposals are considered for funding.


Application to the K2 GO program is typically open to all investigators, including those from outside the U.S. under NASA’s no-exchange-of-funds policy. Investigators who are not affiliated with a U.S. institution are not eligible for funding through this program.

Co-Investigators (Co-Is) affiliated with a U.S. institution are eligible to receive funding under a proposal led by a foreign PI. In this scenario, only a single Co-Investigator per proposal will be considered as a lead PI for funding purposes, and proposals should identify a lead Co-Investigator within the U.S.

In accordance with Public Law 113--76, Division B, Title V, Section 532, NASA cannot support bilateral participation, collaboration, or coordination with China or any Chinese-owned company or entity, whether funded or performed under a no-exchange-of-funds arrangement. See the ROSES-2018 NRA for more information on these restrictions.

K2 GO Cycle 7 Solicitation

The call for K2 GO Cycle 7 proposals has been released and made available at NSPIRES.

Submission process

Target lists and accompanying scientific justifications for Campaign 20 are requested as part of the Cycle 7 Phase-1 submission by August 16, 2018. Based on the peer review of these Phase-1 proposals, a target list will be created and uploaded to the K2 approved targets & programs page in September 2018.

To request funding to support scientific investigations of targets selected for observation in Campaign 20, investigators are required to submit Phase-2 proposals through the NSPIRES website by 23:59 Eastern Time on January 17, 2019. All proposers need to register with NSPIRES in order to submit a Phase-2 proposal. A Phase-1 submission is not mandatory to qualify for Phase-2, however Phase-2 proposals may only utilize targets which have been included in the Campaign 20 target list (for any program).

Detailed instructions for submitting a Phase-2 proposal are as follows:

  1. If new to the NASA Solicitation and Proposal Integrated Review and Evaluation System, NSPIRES, register on the NSPIRES website.

  2. Familiarize yourself with the NASA Research Announcement (NRA) Research Opportunities in Space and Earth Sciences Announcement 2018 (ROSES-2018). This document provides an overview of the NRA process and is a compilation of most solicitations within NASA's Science Mission Directorate.

  3. Read the Cycle 7 K2 Research Announcement. New amendments to the NRA are publicized at NSPIRES. Check this page regularly.

  4. Submit a Phase-2 proposal to NSPIRES by 23:59 Eastern Time on January 17, 2019.

  5. Submit an electronic copy of the target tables via e-mail to the GO Office (keplergo@mail.arc.nasa.gov) before the deadline. You must use the target list table format detailed below.

Proposal content

The generic content of the proposal is described in the 2018 NRA Proposers Guide. Page limits and proposal content within the NRA Guide are amended within the K2 GO Cycle 7 NRA and are summarized in the table below. The right-hand column provides page limits for the package elements. Caveats to the page limits are provided as footnotes. The page limits on this website override the NRA-generic limits within the handbook.

The Scientific/Technical/Management section of the Phase-2 proposal, which consists of text, tables (excluding the target table), and figures must not exceed four pages for proposals in the Small category, or six pages for proposals in the Large category. An additional 0.5 pages is allowed in Large proposals to describe progress the proposers have made to delivering value-added community resources. References and the target table do not count against the four or six page limit, however, the completed package uploaded to NSPIRES for the Scientific/Technical/Management section must not exceed 15 pages. If a large target table extends beyond the 15 page limit then truncate the table so that the page limit is not exceeded and make a note within the proposal that the table has been truncated.

Page limits for the PI and Co-I biographies and current and pending support are defined below, and are separate from the 15 page limit for the Scientific/Technical/Management section. PIs should not feel compelled to meet the page limits, but must submit all items appropriate to their proposal and should not exceed the page limits as defined below.

Required Content for Phase-2 Proposals Page Limit
Table of Contents 1
Scientific Justification/Technical/Management Section, "Small" proposals 4
Scientific Justification/Technical/Management Section, "Large" proposals 6
Target Table as needed
References as needed
PI Biography 2
Co-I Biography 1 per Co-I
Current and Pending Support as needed

Includes text, tables, and figures. References and the required target table do not count against these four or six page limits, but the target table should be truncated in cases where it would cause this specific section to exceed 15 pages.
Investigations that have broadly similar goals and team members to selected Cycle 1-5 proposals may use up to an additional 0.5 pages to describe progress they have made to delivering value-added community resources, but the Scientific/Technical/Management section still must not exceed 15 pages.


  • Although a detailed budget is not requested in Phase-2 proposals, the Phase-2 proposal should include either a statement of work or a table summarizing the work effort. If the statement of work is included in the Scientific/Technical/Management section it will count against the page limit for that section, but a table can be included as a separate section that will not count against the Scientific/Technical/Management section page limit. The statement of work should clearly identify any and all members of the proposing team who would receive funding under the proposed investigation. The funding amounts will be determined formulaically based on target allocation.
  • As part of the NSPIRES submission, the system will request a mandatory Data Management Plan (4000 characters). Proposers are encouraged to explain how the results, data, and source code produced by the investigation will be shared with the public as part of this plan. Guidance on the Data Management Plan requirement can be found at https://go.nasa.gov/ROSESDMP.
  • Large proposals that anticipate delivery of a data product/products to one of the NASA archives (e.g., MAST or the NASA Exoplanet Archive) for curation must also include a letter of acknowledgement from the relevant archive.

Target table format


Pointed observations away from the single stare position of any given field cannot be accommodated by K2; campaign targets are limited to the objects available in the fixed field of view.

Small gaps between the 42 detector CCDs as well as the three dead modules result in additional loss of available objects that would otherwise be within the field of view. A documented target search tool at MAST determines if an object of a particular coordinate lies close to the observable field of view.

The target search tool accesses the Ecliptic Plane Input Catalog (EPIC), which provides physical data, coordinates, magnitudes, and colors, for sources close to K2 silicon. The EPIC is complete only to mV ~ 17; specifications of the catalog are documented here.

It is the proposer’s responsibility to identify targets that are faint or missing from the EPIC. K2 collection of valid data relies on the delivery of accurate celestial positions and magnitudes of each target. Proposals must state the origin for this information, especially if it does not come from the EPIC. Extended targets or targets with high proper motion should also be noted by the proposer.

Determining whether or not desired targets fall on active regions of the focal plane is also the responsibility of the proposer. The Kepler & K2 Science Center provides a tool called K2fov to identify which targets fall upon active silicon. Only those targets within the active fields of view should be proposed.

Note that all investigators must update their version of K2fov to the latest version (v8.0) to take the field position of Campaign 20 into account. K2fov can be updated from the command line using pip:

pip install K2fov --upgrade

The version number of your K2fov installation may be verified using the following command:

python -c "import K2fov; print(K2fov.__version__)"

This must return "8.0.0" or higher. If the number is lower, or if you see an error message, then your installation of K2fov is outdated and must be upgraded. Not upgrading K2fov will lead to unobservable targets being selected!

Target table

All proposals are required to include a target table in a pre-defined format to specify desired observing modes and other needed parameters.

The target tables generally provide all the information required by the Kepler & K2 Science Center to incorporate sources within the observing list. Table fields are described below with an example. If a proposal includes targets within multiple campaign fields, then a separate target table should be prepared for each field.

An example of a valid target table is shown in the image below. The corresponding .xls file can be downloaded here.

Template Target Table

A definition of each column is included in the below table.

Attribute Description
Object The Ecliptic Plane Input Catalog (EPIC) ID number. This attribute can be determined by using the K2 EPIC Target Search page. The EPIC ID is coupled to celestial coordinates and magnitudes. If the proposed target does not have an EPIC ID number please use a unique identifier, common or catalog name for this source, and supply the J2000 celestial coordinates in the Right Ascension and Declination columns of your target table.
Right Ascension Right Ascension (J2000) of the center of the desired aperture. Celestial coordinates are only required if the target is not listed in the K2 EPIC Target Search page. Adhere to decimal degree format.
Declination Declination (J2000) of the center of the desired aperture. Celestial coordinates are only required if the target is not listed in the K2 EPIC Target Search page. Adhere to decimal degree format.
Kp The apparent magnitude of the target in the Kepler bandpass. The combination of celestial coordinates and magnitude are the primary data required by the Kepler & K2 Science Center to calculate target pixel masks. The Kepler magnitude for most sources can be obtained from the K2 EPIC Target Search page. If no Kepler bandpass magnitude is provided in the EPIC, it can be estimated. If the magnitude entered here is brighter than the EPIC magnitude, then the user-supplied magnitude will be adopted. For highly-variable stars, list the brightest predicted magnitude.
Cadence Mode The observing mode requested. Long cadence (30-minute) mode or Short cadence (1-minute) mode.
δRA Proper motion of the target in units of arcsec per year. This information is optional and should only be provided if the proposer disagrees with the proper motion provided in the EPIC.
δDec Proper motion of the target in units of arcsec per year. This information is optional and should only be provided if the proposer disagrees with the proper motion provided in the EPIC.
Extent The radius of the semi-major axis of an extended target such as a galaxy. To reiterate, this is the radius, NOT the diameter i.e. the furthest distance that structure extends from the target coordinates provided. This column should be ignored if all targets are point sources.
Comments If a target is non-standard, provide a brief description of non-standard table entries including: (a) user-supplied magnitude; (b) user-supplied coordinates; (c) extended sources; (d) the amplitude of highly variable stars, (e) high proper motion stars; (f) custom mask requests. Comments should be expanded upon within the text of the science justification of the proposal.

A blank template target table for insertion into the proposal can be downloaded here.

Target tables for each campaign are required to be submitted via email directly to the Kepler & K2 GO Office for Phase-1 proposals submitted in response to GO Cycle 7. They do not need to be embedded within the text of the proposal.

Special instructions for moving targets

If you plan to submit a proposal for a Solar System (moving) target, we recommend that you adhere to the following guidelines:

  1. Only include a single row in your target table for each moving target. You are not required to include coordinates as long as you provide the name or number of the object exactly as it is known in JPL Horizons.
  2. State (a) the minimum and (b) the ideal number of days during which each target needs to be observed to meet the goals of your scientific investigation.
  3. Provide a rough estimate of the pixel cost corresponding to both the minimum and ideal observing durations for each target. Please get in touch with us at keplergo@mail.arc.nasa.gov if you require assistance with this.


  • What are the proposal deadlines?
    Phase-1 proposals for Cycle 1 are due August 16, 2018 by 23:59 Eastern Time via e-mail to keplergo@mail.arc.nasa.gov. Phase-2 proposals for Cycle 7 are due January 17, 2019 by 23:59 Eastern Time via NSPIRES.

  • What are the anticipated dates of the campaigns included in the current solicitation?
    Campaign 20 is scheduled to run from Oct 15, 2018, through Jan 05, 2019.
    Start and stop dates for all campaigns are approximate, flexible and could be overtaken by unanticipated operational events or the spacecraft running out of fuel.

  • Where is the field located on the sky
    The pointings for all K2 campaigns can be found on the fields page. Target lists for each of these fields can be found on the K2 approved targets & programs page.

  • Should I submit one proposal or two?
    In the interest of efficiency, proposers are requested NOT to provide separate proposals with identical science cases for each of the campaigns. If the same science goals are spread across multiple campaigns, please provide one science justification and up to three target tables, one for each field.

  • Should I apply for targets that do not fall on silicon?
    Please, no. Proposing off-silicon targets is a waste of energy for proposers, reviewers and project staff. Use K2fov and apply only for targets that fall upon silicon (output flag "2").

  • What is the K2 Ecliptic Plane Input Catalog (EPIC)?
    Proposers are asked to submit targets using identifiers from the EPIC. The EPIC plays the same role for K2 that the Kepler Input Catalog (KIC) played for Kepler target selection. The primary purpose of the catalog is to define photometric apertures for each potential target by providing celestial positions and Kepler bandpass magnitudes. EPIC parameters are produced by source matching existing multi-band catalogs and calculating color corrections for the Kepler bandpass. Documentation describing the compilation of the EPIC is provided here.

  • What type of science targets can be proposed?
    There are no constraints on the type of science or science target that can be proposed.

  • How many targets can be proposed?
    Both long cadence (30-min exposure) and short cadence (1-min exposure) targets will be observed during each campaign. There are no constraints whatsoever on the number of targets that can be proposed. The total long cadence target list is expected to be between 10,000 and 20,000 targets per campaign. Approximately 50 to 100 short cadence targets are anticipated per campaign.

  • How many pixels around each target will be collected?
    The number of pixels collected for each target depends on the target's Kepler magnitude. For Kp = 12, the target pixel masks include approximately 100 pixels. Extra halos of pixels will be added to K2 masks in order to capture uncertainties in field acquisition (currently a pixel) and pointing drift over time (currently a pixel).

  • Are there bright or faint magnitude limits?
    There are no faint limits upon the brightness of targets that can be proposed. Bright targets will be significantly more expensive in terms of pixel usage. Targets brighter than 3rd magnitude in the Kepler bandpass cannot be observed because charge bleeding along CCD pixel columns will fall into collateral pixels of the detector. Bright targets (Kp < 9) and short cadence targets require strong, compelling science cases.

  • How do I propose a moving target?
    The proposal process is the same for a Solar System or moving target as it is for other targets. However, proposers should take note of recommendations when creating the target table for moving targets.