The KELT Follow-Up Network: Crowd-Sourced Photometry

Rob Siverd (LCOGT)Hotwired IV

Kilodegree Extremely Little Telescope Wide-field photometric survey for bright

transiting exoplanets (~15 discovered!) Coarse pixel scale (23 arcsec, defocused) Wide bandpass Amateur- and commercial-grade hardware Stable (but ugly) PSF Difference Imaging Pipeline (ISIS-based) Bright, high-value targets (8 < V < 10)

What is KELT?

Why 8 < V < 10?

KELT-North and KELT-South

Pepper, J., 2012, “The KELT-South Telescope”, PASP, 124, 230

Pepper, J., et al. 2007, "The Kilodegree Extremely Little Telescope (KELT): A Small Robotic Telescope for Large-Area Synoptic Surveys", PASP, 119, 923

Pipeline and reductions:Siverd, R. J., et al. 2012, “KELT-1b: A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-mass Companion Transiting a Mid-F Star”, ApJ, 761, 123

Bandpass

Bandpass

~50,000 stars per field

1% error for V < 10

Performance

Observing Fields

KELT’s FOV

26°x26°

26°x26°

4.6’ x 4.6’

KELT-North

KELT’s FOV

26°x26°

4.6’ x 4.6’4.6’ x 4.6’

Faulkes Telescope NorthKELT-North

KELT’s FOV

26°x26°

4.6’ x 4.6’4.6’ x 4.6’

Faulkes Telescope NorthKELT-North

KELT’s FOV

Depth uncertainty due to blending/dilution (consequence of our DIA pipeline)

Source confusion (giant pixels) False positives due to imperfect calibration

and pointing issues (e.g., hot pixels)

Extra Photometry Required

~50 telescopes around the world Sites include backyards and pro

observatories Apertures from 0.3m (12”) to 2m Wide variety of filters available Amateurs, professionals, and educators Observations taken at leasure (or request) Results emailed to Google Group Key software contributions from

collaborators

Solution: Photometry Crowd

Solution: Photometry Crowd

Typical Results

Candidate Management (Google Docs)

Public version (exoplanets.org):http://astro.swarthmore.edu/transits.cgi

Public code:http://hven.swarthmore.edu/~jensen/tapir.htmlhttp://adsabs.harvard.edu/abs/2013ascl.soft06007Jhttps://github.com/elnjensen/Tapir

Candidate Dissemination: Tapir

Tapir Search Interface

Example Output: BOS

Fun! Scientific interest Authorship or coauthorship Learning new skills Challenging Bored of “pretty pictures” …

Motivation and Incentives