The APACHE Project: searching for transiting planets around cool stars

Mario DamassoOAVdA & Dept. of Physics and Astronomy (University of Padova)

on behalf of the APACHE team

Introducing APACHE

APACHE stands for A PAthway toward the Characterization of Habitable Earths

It is a long-term targeted, small field photometric survey aimed at discovering transiting small-size exoplanets around a well-defined sample of hundreds of nearby dM0-dM5 stars, using an array of 400-mm telescopes

complementary to the MEarth survey

The APACHE photometric database will greatly contribute to the astrophysics of the M dwarfs, throught the characterization of their micro variability (rotation, activity)

Two telescopes founded by Cassa di Risparmio di Torino

The primary node

The Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA)

A detailed feasibility study has been carried out to demonstrate that the OAVdA is a well-poised site where this long-term survey can be based (Damasso et al., PASP, 2010).

The APACHE Team

The OAVdA team

Enzo Bertolini

Andrea Bernagozzi

Paolo CalcideseAlbino Carbognani

Davide Cenadelli

Jean Marc ChristilleMario Damasso

Paolo Giacobbe

The INAF-OATo team

Luciano LanteriMario G. Lattanzi

Richard Smart

Alessandro Sozzetti (P.I.)

Milestones of the APACHE Project

A site characterization/feasibility study in 2009(Damasso et al., PASP, 2010)

A pilot study in 2010 and part of 2011 (Giacobbe et al., MNRAS, 2012)

The long-term photometric survey

We presented the results of a 1.5 year-long photometric monitoring campaign of a sample of 23 nearby (d < 60 pc), bright (J < 12) dM stars.

This survey has been carried out with the pre-existing instrumentationand was planned as a necessary training for the definition and fine tuning of the APACHE survey.

The pilot study

2010 NOW

Sensitivity to transits (planets of given radius and period) 0.5 < P < 5 days

0.5 < P < 1 day1-2.2 RStarting from our real data, we simulated:

a) 1000 random, uniformly distributed periods in the range 0.5 – 5 days

b) 100 random, uniformly distributed phases for each period

c) 4 amplitudes of transit signal depth (2%, 1.5%, 1% and 0.5%) 0.8-4.5 R

400,000 light curves/target

The Apaches

Mount:GM 2000 - QCI, 10 Micron

CCD:Fli PROLINE KAF-1001°Array Size: 1024 x 1024Pixel size: 24 μmPixel scale 1.5 arcsec/pixelField: 26.3' X 26.3'

Four 400-mm telescopes are installed and functioning

Telescope: RC Pro 400 LT f/8.4 Weight: 42 kgOptical set glass: LK7 for LT model

Preparing to the survey…

The APACHE input catalogue

The telescope automatic control system

The observing strategy

Credit: Giovanni Antico (www.gantico.com)

Pipelines for data reduction and analysis

Real-time photometry Post-observations photometry

TEEPEE Robin

Two independent pipelines

TSE – Transit SEntinel

Intra-night ensemble differential photometry

Intra-night ensemble differential photometry Multi-epoch differential photometry (stellar rotation) Automatic search for transit-like signals Discovery and first characterization of new

variable stars

Preliminary resultstargets with small intra-night RMS

Nights of observation (since July, 9): 73Number of different fields observed: 93Mean number of fields per telescope per night (in winter): 12

time

time

time

time

Preliminary resultsa close eclipsing binary star

time

Original data from the telescope APACHE#1

Follow-up with the 810-mm telescope in OAVdA

Evidence for spots?Primary minimum (2012/10/22)

Secondary minimum (2012/10/24)

Reported in ASAS photometry ROSAT sources. I.(Acta Astronomica vol. 62, 67-95, March 2012)

V=12.4 (APASS)dM0, H-alpha emission (Riaz et al., 2006)X-ray emission (ROSAT)Orbital period: 0.5667 days

Preliminary resultsnew variable stars

CzeV188EW, P = 0.247 days VSX J214004.5+273835

EW, P = 0.289 days

VSX J194934.6+314713EA, P = 0.523 days

>

GSC 04463-01592EB, P = 0.642 days

...and more than this!

For more details about the design and the status of the survey see Christille et al. poster!

Support observationsthe Asiago Red Dwarf Survey (ARDS)

The GAPS observational program

(see the Claudi’s talk of yesterday)

One of the goals of GAPS is the determination of the frequency of potentially habitable low-mass planets for the nothern low-mass stars.

Some of the GAPS targets have been selected from the APACHE catalogue, and those targets have been assigned the highest priority in the APACHE schedule.

RV and photometric data are collected during the same period and, if the skycollaborates, also during the same nights.

The APACHE-Gaia synergyFor a typical target with V~14 at d~20 pc, Gaia will provide parallaxes with σ(π)/π~0.1%!

A precise characterization of the host star fundamental parameters for a precise knowledge of the planet bulk properties (e.g. “GJ 1214 reviewed”, Anglada-Escudé et al., A&A submitted)

Precise measurements of the trigonometric parallax for the APACHE targets imply:

Their intrinsic luminosity, mass and radius could be significantly updated

Improved metallicities using photometric methods

For bright targets with transiting planets, these updated values for the host stars (especially the radius) imply a precise determination of the planet radius. Combined with exquisite RV data (e.g. HARPS-N), the density of the planet can be precisely determined.

http://apacheproject.altervista.org/

THANKS FOR YOUR ATTENTION

V mag distribution of the APACHE targets

~12.5-13