Campaign 9 of K2: News from the K2 team

Transcription

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 K2 Guest Observer Office (NASA Ames)

2 Kepler was launched on 6 March 2009 Geert Barentsen (@GeertHub) 100 Mpixel array (100 deg 2 ) 1 or 30 min cadence wide passband (~V+R+I) 0.95-m Schmidt

3 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 Kepler now changes its pointing every 80 days Feb-Apr 2015 Aug-Nov May-Aug Apr-Jul Mar-May 2014 Nov-Feb 2015 => K2 mission

6 What is K2? K2 is a two-reaction wheel mission utilizing the Kepler spacecraft Targets 100 deg 2 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 Geert Barentsen (@GeertHub)

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. 2015

10 After correction, the photometric performance of K2 is very similar to Kepler prime Vanderburg et al. 2015

11 Geert Barentsen K2 Campaign 9

12 K2 will observe the bulge between 7 Apr 2016 and 1 Jul

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

14 View from above on 15 May 2016 Spitzer Backward facing ( Velocity Vector) Kepler Sun Earth

15 View from above on 15 May 2016 Spitzer Sun Kepler Forward facing (+ Velocity Vector) Earth

16 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. Geert Barentsen (@GeertHub)

17 Schedule (K2C9 white paper, Henderson et al 2016) Exact times will be known ~2 months in advance when the Deep Space Network schedule settles Geert Barentsen

18 Geert Barentsen K2 C9 Science Team

19 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. Geert Barentsen (@GeertHub)

20 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). Bennett Henderson Hogg Penny Street Joined by Radek Poleski, co-investigators, K2 personnel. Geert Barentsen (@GeertHub)

21 K2C9 Science Team (III) Achievements of the team so far include: the white paper (arxiv: ); 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! Geert Barentsen (@GeertHub)

22 Geert Barentsen K2 C9 Technical Aspects

23 Preliminary pixel selection (Poleski) Module 15 Module 10 Final selection will also include thousands of small masks spread across the field to cover DDT targets & ongoing events

24 Preliminary pixel selection (Poleski) Channel 49 Channel 30 Channel 52 Channel 31 Channel 32

25 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. Geert Barentsen (@GeertHub)

26 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. Geert Barentsen (@GeertHub)

27 Mid-campaign offset (II) Between C9a and C9b, the pointing will shift by 0.5px.

28 Geert Barentsen Support from the K2 Team

29 We are happy to help! Kepler GO office: Tom Barclay, Knicole Colon, Geert Barentsen us at Tweet us Visit our new website: Geert Barentsen

30 K2C9 Visibility App Geert Barentsen

31 K2C9 Visibility App Geert Barentsen

32 K2fov : a Python package for querying and plotting K2 Campaign fields Geert Barentsen (@GeertHub)

33 We will be releasing the K2 C9 data 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. Geert Barentsen (@GeertHub)

34 Accessing raw K2 data The kadenza Python package makes raw data accessible: A 10-day sample of raw C0 data has been posted at Geert Barentsen (@GeertHub)

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 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! Geert Barentsen

37 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?) us at if you are interested. (Non US-citizens must apply >1 month in advance.) Geert Barentsen

38 Geert Barentsen Future opportunities

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

40 C11 C9

41 A second microlensing experiment in C11? K2 will survey the Northern Bulge during Campaign 11: 24 Sep Dec 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 Geert Barentsen (@GeertHub)

42 VPHAS+ Survey 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 arcsec. Public band-matched catalogue available (daophot psf photom) Geert Barentsen

43 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. Geert Barentsen (@GeertHub)