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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
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43 slides
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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) http://keplerscience.arc.nasa.gov -
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) -
As of 2013, the solar radiation pressure needs to be
balanced on the solar panels to minimize torques around the roll axis -
Mar-May 2014 May-Aug 2014 Aug-Nov 2014 Nov-Feb 2015 Feb-Apr 2015
Apr-Jul 2015 Kepler now changes its pointing every 80 days 0 1 2 3 4 5 9 => “K2 mission” -
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 -
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”) -
After correction, the photometric performance of K2 is very similar
to Kepler prime Vanderburg et al. 2015 -
9 K2 will observe the bulge between 7 Apr 2016
and 1 Jul 2016 -
Earth Kepler Spitzer View from above on 15 May 2016
Sun “Backward facing” (—Velocity Vector) -
Earth Kepler Spitzer View from above on 15 May 2016
Sun “Forward facing” (+ Velocity Vector) -
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. -
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) -
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. -
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 -
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! -
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 -
Channel 31 Channel 32 Channel 52 Channel 49 Channel 30
Preliminary pixel selection (Poleski) -
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. -
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. -
Mid-campaign offset (II) Between C9a and C9b, the pointing will
shift by 0.5px. -
Geert Barentsen (@GeertHub) We are happy to help! • Kepler
GO office: Tom Barclay, Knicole Colon, Geert Barentsen • E-mail us at [email protected] • Tweet us at @KeplerGO • Visit our new website: http://keplerscience.arc.nasa.gov -
Geert Barentsen (@GeertHub) “K2fov”: a Python package for querying and
plotting K2 Campaign fields https://github.com/KeplerGO/K2fov -
Geert Barentsen (@GeertHub) 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) Accessing raw K2 data • The “kadenza”
Python package makes raw data accessible: https://github.com/KeplerGO/kadenza • A 10-day sample of raw C0 data has been posted at https://archive.stsci.edu/missions/k2/c0_raw_cadence_data/ -
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! -
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! -
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 [email protected] if you are interested. • (Non US-citizens must apply >1 month in advance.) -
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) -
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. -
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 -
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.