California Planet Search

The California Planet Search (CPS) is an organization of astronomers that facilitates observations and the production of precise Doppler time series and related data from the HIRES and the Keck Planet Finder (KPF) spectrometers at the W. M. Keck Observatory (WMKO) and from the Levy Spectrometer on that Automated Planet Finder telescope at Lick Observatory.1 Unlike typical research collaborations, CPS is not organized around specific scientific goals. Rather, it provides the infrastructure for other research collaborations that have specific scientific goals to execute their observations using the above telescopes. CPS handles the production of data from the scheduling and execution of observations through the standardized reduction of raw data products (e.g., echelle spectra) into refined data products (e.g., radial velocities). It is the responsibility of the collaborating research groups (through their principal investigators) to select targets, use the refined data products in scientific analyses, interpret the results, and write papers. Telescope scheduling with CPS allows participants to have observations spread over the observing semester, instead of being concentrated in the allocated telescope time (e.g., one night at Keck). This facilitates science projects with cadence requirements that are not schedulable by an individual PI. The governing document for CPS is titled ‘California Planet Search – Organization and Procedures’ and is publically available here.

Who is part of CPS already?

Participating Scientists Fei Dai, BJ Fulton, Sam Halverson, Andrew Howard, Dan Huber, Howard Isaacson, Stephen Kane, Bruce Macintosh, Erik Petigura, Paul Robertson, Lauren Weiss, Samuel Yee, Lea Hirsch, Malena Rice, Adam Benjamin Langeveld, Theron Carmichael, Steven Giacalone, Tansu Daylan, Gummi Stefansson.

Affiliates Aaron Householder, Jared Kolecki, Alex Polanski, Pranav Premnath, Claire Rogers, Ryan Rubenzahl, Alex Thomas, Emma Turtleboom, Judah Van Zandt, Jingwen Zhang, Marie Tagliavia, Rena Lee, Nick Saunders, Sabrina Weldon, David Shaw.

How do I join?: The CPS document describes the rights, responsibilities, and procedures for membership.

  1. Send a signed copy of the CPS document (complete with your expected role, PI sponspor, and dates of membership) to the Membership Chair (Jingwen Zhang, jwzhang@ucsb.edu).
  2. Members will be given access, as needed, to internal slack channel to facilitate communication, and collection of data and distribution of data. Contact the CPS Lead (ahoward@caltech.edu) if you think the slack access you need is different from what you have.
  3. Members will be given access, as needed, to Jump to facilitate curation and distribution of data. Contact the CPS Council if you think the Jump access you need is different from what you have.

I want to pool telescope time with CPS this semester to optimize my science; what should I do? If you are interested in proposing to collaborate with the California Planet Search on cadence observations with KPF, HIRES, or APf, please fill out this FORM2 Full consideration will be given to requests submitted by March 7, 2025 (for 2025B proposals) though later requests will be reviewed. (NASA and other proposals due before then should submit responses using the form as soon as possible.) Collaboration with CPS is not required to use these instruments. Technical information about KPF is available on WMKO’s website. See also the Exposure Time Calculator page and the associated Github code. See these SLIDES from a breakout session at the 2023 Keck Science Meeting for information about KPF’s current performance. Time permitting, CPS can provide a few sentence description of KPF’s performance and expectations for queue operations; this can be provided or proposals that have been submitted using the above form and endorsed by CPS. For HIRES, CPS will no longer support a minimal queue as of 2025A, but can still offer assistance to reduce HIRES data, upon request. To pool awarded telescope time with CPS, you will need to join as a participating scientist or affiliate.

  1. CPS is independent of WMKO, Lick Observatory, and the Keck Observatory Archive (KOA). Users of the instruments mentioned above are not required to collaborate with CPS. ↩

  2. Note that completing the form for collaboration with CPS requires logging into a Google account because you will be asked to upload a PDF copy of your draft proposal, which involves behind-the-scenes use of Google Drive. ↩