Campaign 9 of K2: News from the K2 team

Campaign 9 of K2: News from the K2 team

A talk by Geert Barentsen & Tom Barclay
 for the 20th Microlensing workshop in Paris
 on 14 January 2016.


Geert Barentsen

January 14, 2016


  1. Campaign 9 of K2:
 News from the K2 team A

    talk by Geert Barentsen & Tom Barclay
 for the 20th Microlensing workshop in Paris
 on 14 January 2016.
 K2 Guest Observer Office (NASA Ames)
  2. Geert Barentsen (@GeertHub) Kepler was launched on 6 March 2009

    0.95-m Schmidt 100 Mpixel array (100 deg2)
 1 or 30 min cadence wide passband (~V+R+I)
  3. 2009-2013 Kepler prime observed ~200,000 stars

  4. As of 2013, the solar radiation pressure needs to be

    balanced on the solar panels to minimize torques around the roll axis
  5. Mar-May
 2014 May-Aug
 2014 Aug-Nov
 2014 Nov-Feb
 2015 Feb-Apr

 2015 Kepler now changes its pointing every 80 days 0 1 2 3 4 5 9 => “K2 mission”
  6. Geert Barentsen (@GeertHub) What is K2? • K2 is a

    two-reaction wheel mission
 utilizing the Kepler spacecraft • Targets 100 deg2 fields
 during 80-day campaigns • Limited by on-board storage:
 3-5 Mpix per cadence • Community mission: all targets selected through peer review • Open data
  7. The roll motion of the spacecraft is visible in K2

    data taken towards focal plane edges Note: thrusters correct
 the attitude every ~6h
 (cf. “jumps”)
  8. The roll motion causes stars to move;
 introducing systematics

  9. These systematics can be modelled (“detrended”) accurately Foreman-Mackey et al.

  10. After correction, the photometric performance of K2 is very similar

    to Kepler prime Vanderburg et al. 2015
  11. Geert Barentsen (@GeertHub) K2 Campaign 9

  12. 9 K2 will observe the bulge between
 7 Apr 2016

    and 1 Jul 2016
  13. Earth Kepler Spitzer View from above on 15 May 2016

    0.8 AU Sun
  14. Earth Kepler Spitzer View from above on 15 May 2016

    Sun “Backward facing”
 (—Velocity Vector)
  15. Earth Kepler Spitzer View from above on 15 May 2016

    Sun “Forward facing”
 (+ Velocity Vector)
  16. Geert Barentsen (@GeertHub) C9 operations have been in preparation for

    8 months • Engineers have worked on 53 issues related to C9, including: • turning the spacecraft in the opposite direction; • adding a mid-campaign downlink to obtain more pixels; • overcoming data compression issues; • enabling fast access to the raw data; • enabling ongoing events to be added to the target list. • Please credit the efforts from the engineers at NASA Ames & Ball Aerospace where you can.
  17. Geert Barentsen (@GeertHub) Schedule Exact times will be known ~2

    months in advance
 when the Deep Space Network schedule settles (K2C9 white paper, Henderson et al 2016)
  18. Geert Barentsen (@GeertHub) K2 C9 Science Team

  19. Geert Barentsen (@GeertHub) K2C9 Science Team • To maximize the

    scientific return, NASA has funded 
 a C9 Microlensing Science Team. • The team has been recruited to … • make recommendations on the observation planning; • facilitate coordinated ground-based observations; • detect, characterize, and understand the events observed by K2,
 e.g. address under-sampled crowded field photometry. • All data, products, results obtained by the team are expected to be made public.
  20. Geert Barentsen (@GeertHub) K2C9 Science Team (II) • Team was

    selected in Oct 2015 through a peer-review process. • Selected PIs are David Bennett (Goddard), Calen Henderson (JPL/Caltech), David Hogg (NYU), Matthew Penny (Ohio), and Rachel Street (LCOGT).
 • Joined by Radek Poleski, co-investigators, K2 personnel. Bennett Henderson Hogg Penny Street
  21. Geert Barentsen (@GeertHub) K2C9 Science Team (III) • Achievements of

    the team so far include: • the white paper (arXiv:1512.09142); • presentations at the AAS (6 Jan) and today’s workshop (14 Jan); • setting up an open mailing list and wiki; • guiding NExSci to adapt the ExoFOP system for C9; • advocacy for UKIRT time (successful — NASA funds 180h); • advocacy for later K2 deadlines to add ongoing events (successful); • a strategy to obtain lightcurves from the K2 pixel data. • … • See other talks today!
  22. Geert Barentsen (@GeertHub) K2 C9 Technical Aspects

  23. Preliminary pixel selection (Poleski) Module 10 Module 15 Final selection

    will also include thousands of small masks spread across the field to cover DDT targets & ongoing events
  24. Channel 31 Channel 32 Channel 52 Channel 49 Channel 30

    Preliminary pixel selection (Poleski)
  25. Geert Barentsen (@GeertHub) Pixel selection deadlines • Pixels need to

    be selected by 25 Jan 2016 • Operators need to prepare, validate, and uplink spacecraft command sequences in a timely fashion. • Science Team advocated for a later deadline to be able to include ongoing events; engineers have committed to append a small number of targets (~100 i.e. <0.5%) at a later deadline.
 • Targets for C9a (7/Apr-18/May) can be added up to 1/Mar. • Targets for C9b (22/May - 1/Jul) can be added up to 25/Apr.
  26. Geert Barentsen (@GeertHub) Mid-campaign offset • K2 photometry is challenged

    by intra- and inter-pixel sensitivity variations which come into play due to the spacecraft roll. • Dithering would offer a better handle on these variations than the rolling motion alone. • Dithering before or during C9 was deemed too risky;
 a mid-campaign offset will be performed instead.
  27. Mid-campaign offset (II) Between C9a and C9b, the pointing will

    shift by 0.5px.
  28. Geert Barentsen (@GeertHub) Support from the K2 Team

  29. Geert Barentsen (@GeertHub) We are happy to help! • Kepler

    GO office: Tom Barclay, Knicole Colon, Geert Barentsen • E-mail us at • Tweet us at @KeplerGO • Visit our new website:
  30. Geert Barentsen (@GeertHub) K2C9 Visibility App

  31. Geert Barentsen (@GeertHub) K2C9 Visibility App

  32. Geert Barentsen (@GeertHub) “K2fov”: a Python package for querying and

    plotting K2 Campaign fields
  33. Geert Barentsen (@GeertHub) We will be releasing the K2 C9

 as soon as possible • Release plan: • 2016 May 24: C9a raw images • 2016 July 6: C9b raw images • 2016 Sep 26: C9a + C9b reduced images
 (+ lightcurves for isolated targets)
 • Data will be public. No old-fashioned proprietary period! • We encourage other facilities to embrace the openness.
  34. Geert Barentsen (@GeertHub) Accessing raw K2 data • The “kadenza”

    Python package makes raw data accessible: • A 10-day sample of raw C0 data has been posted at
  35. We have unearthed the raw PRF characterization data (April 2009)

    • Dithering data obtained during commissioning. • Talk to me if you’re interested in obtained these files!
  36. Geert Barentsen (@GeertHub) Press and outreach support • We have

    skilled PR and outreach staff embedded within the Kepler/K2 office • They are experts at crafting press releases and preparing visuals • They can coordinate with your institutions • Please keep us updated on likely news stories!
  37. Geert Barentsen (@GeertHub) Visiting the Kepler/K2 team • We can

    host visitors at NASA Ames (California). • Opportunity to interface directly with instrument expertise. • Would particularly benefit those tackling K2 data reduction.
 (Hack week?) • E-mail us at if you are interested. • (Non US-citizens must apply >1 month in advance.)
  38. Geert Barentsen (@GeertHub) Future opportunities

  39. Geert Barentsen (@GeertHub) Future target & funding opportunities 11 12

    13 • A call is open for proposals related to Campaigns 11, 12, 13 • Step 1 deadline: Feb 5, 2016 • Step 2 deadline: Mar 4, 2016 • Funding via formula ($30,000 to $150,000)
  40. C9 C11

  41. Geert Barentsen (@GeertHub) A second microlensing experiment in C11? •

    K2 will survey the Northern Bulge during Campaign 11:
 24 Sep 2016 - 8 Dec 2016. • Subject to K2 passing the senior review. • Likely K2’s final visit to the Galactic Center & Bulge. • We encourage proposals from the microlensing community. • Microlensing proposals will compete with other science; need to request a pixel budget that is justifiable. (Think 10%-30%?) • Step 1 deadline is 5 Feb 2016.
  42. Geert Barentsen (@GeertHub) • ESO public survey using the 2.5-meter

    VLT Survey Telescope (VST) in Paranal. • u, g, r, i, Halpha imaging to 21st magnitude (complements VVV in optical). • Median seeing 0.8-0.9 arcsec. • Public band-matched catalogue available (daophot psf photom) VPHAS+ Survey
  43. Geert Barentsen (@GeertHub) Summary & closing remarks • K2 Campaign

    9 offers an exciting opportunity for microlensing. • The experiment represent a significant investment of public resources from NASA and Kepler/K2 into microlensing science. • We encourage the entire community to get together to make C9 a success — this is an opportunity to strengthen the field and secure future resources.