CoRoT&in&Brief&
• «&Small&»&CNES&Mission&+&Belgium&+&Germany&+& Austria&+&Spain&+&Brasil+&ESA& Lessons&from&CoRoT& • 3rd&PROTEUS&mission&(minisat)& Marc&Ollivier& • Double&program&:&asteroseismology&and&search&for& Ins5tut&d’Astrophysique&Spa5ale&d’Orsay& planetary&transits& • Launch&:&27&Dec&2006&:&Soyouz&Starsem&2b&from& LESIA&–&Observatoire&de&Paris& Baïkonour& & • Circular&polar&orbit&at&896&km&& & • Loss&of&detec5on&chain&2&in&March&2009& • Loss&of&detec5on&chain&1&in&Nov&2012& & • End&of&the&mission&june&2013& • End&of&opera5ons&june&2014&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 2&
The&CoRoT&observatory& The&CoRoT&satellite&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 3& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 4& &&&&&The&focal&plane& CoRoT&:&Observa5on&and&orbital& constraints&
1.3 ° secondary targets (≤ 9) * * • faint stars (11-16) main target (≤ 6) * • • * * 12000 targets 10 targets! sampling 8.5 min sampling 1 s * (32 s.) to 32s * • * * • * field of view
Seismology field Exoplanet field highly defocussed On focus + bi-prism CHEOPS&Workshop&_&Madrid&_&18&june&2015& 6& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 5&
Modeling&of&op5cal&chain&
1st&lesson&:&it&is&necessary&to& understand&as&much&as&possible& how&the&instrument&works&and& responds&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 7& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 8& Modeling&of&op5cal&chain& PSFs&Huygens&at&INFA2&point&
Measured&PSFs& Computed&PSFs&
Defoc¶bole&=& 0mm&
Defoc¶bole&=& +10mm&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 9& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 10&
Comparing&simula5on&and&measurements& Defining&the&detec5on&chain&
Diamètre RMS @ 500 nm 12 40 10 35
30 8
(pixels) 25 6 20 RMS 4 15
10 simus 2 Diamètre 5 mesures INFE2 0 mesures INFE2_focus 0 -10 -5 0 5 10 -60 -40 -20 0 20 40 60 80 Defoc parabole (mm)
Dimension X @ 500nm (perpendiculaire à la dispersion) Dimension Y @ 500nm (direction de la dispersion) 45 35
40 30 35 25 30
25 20
20 15 15 10 mesures INFE2 10 mesures INFE2 5 simus 5 simus mesures INFE2_focus mesures INFE2_focus 0 0 -50 -30 -10 10 CHEOPS&Workshop&_&Madrid&_&18&june&2015&30 50 -50 -30 -10 10 30 11&50 CHEOPS&Workshop&_&Madrid&_&18&june&2015& 12& And&checking&the&specifica5ons& Calibra5ng&the&detec5on&chain& PRNU&
PRNU&@&450,&650,&900&nm&(δλ=10nm)& &and&880&nm&(δλ=80nm)&
Data&given&by&E2V&
Auvergne&et&al&(2009)& Lapeyrere&(2006)&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 13& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 14&
Calibra5ng&the&detec5on&chain& CCD&gain&varia5on&with&T& Bright&star&channel&
Lapeyrere&(2006)& Lapeyrere&(2006)&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 15& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 16& CCD&QE&varia5ons&with&T& Well&capacity&and&satura5on&
Lapeyrere&(2006)& Lapeyrere&(2006)&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 17& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 18&
Well&capacity&and&satura5on& Well&capacity&and&satura5on&
Lapeyrere&(2006)& Lapeyrere&(2006)&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 19& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 20& Well&capacity&and&satura5on& Cross&talks&
Faint&stars&channel&(32s)&
Bright&stars&channel&(1s)&
Lapeyrere&(2006)& Auvergne&et&al&(2009)& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 21& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 22&
CCD&satura5on&
Lesson&2&:&it&is&necessary,&but¬& always&sufficient& Some&stars&saturate&the&DAC&& before&the&CCD&(i.e&:&FWC&much& &larger&than&measured&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 23& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 24& The&baffle&efficiency&
Lesson&3&:&the&worst&is¬& necessary&mandatory&
Rejec5on&~1013&:&difficult&to&model,&impossible&to&measure&in&the&lab&
Auvergne&et&al&(2009)& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 25& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 26&
Preparing&the&exploita5on&phase&
• Data&reduc5on&pipelines&should&be&ready&before&the& launch& • They&should&have&been&tested&on&«&real_like&»&data& Lesson&4&:&you&should&be& (format,&dynamics&range…)& • You&should&know&what&you&expect…& prepared&to&work&on&your&data& – Biases&& – Noise& • You&should&be&prepared&to&correct&what&you&expect& • You&should&be&prepared&to&correct&what&you&don’t& expect& • You&should&expect&what&you&don’t&know&how&to& correct&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 27& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 28& Preparing&the&exploita5on&phase&
• Simulated&data&are&always&simulated&data& • Don’t&be&too&proud&of&you&if&you&manage&to& Lesson&5&:&even&if&your&pipelines& extract&signal&from&simulated&data&:&real&biases& are&(finally!)&ready,&you&will&need& and&noises&should&have&been&forgoren&or&under_ es5mated…&(I’am&joking,&blind&tests&are&useful&!!!)& to&improve&them&con5nuously& & (because&5me&is&a&perpetual& instrument&killer…)&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 29& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 30&
Inves5ga5on&tools& Protons&impacts&
LRa06& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 31& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 32& Protons&impacts& Effects&of&the&radia5ons&
• Drop&of&the&overall&transmission&of&the&dioptric&chain&(objec5ve&(6&lenses),& window,&prisms)& • Drop&of&the&quantum&efficiency& – Es5mated&over&1&run&dura5on&(5&months)&and&several&years&when&a&star&is&re_observed&
&
Photometric&loss&of&about&10%&in&6&years&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 33& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 34&
Charge&transfer&inefficiency& Dark¤t&
• CTI&=&1_CTE& • Negligible&at&CoRoT’s&launch& • CTI=&10_4&for&STIS&(HST)&aver&7&years&at&alt&=& • Increase&with&5me&(and&radia5on&exposi5on)& 500&km& A&slope&appears&on&the&background&due&to&the&readout&5me& • Loss&of&about&10%&max&of&the&e_&during&the& .& Integra5on&:&32&s&& .& readout&process,&i.e&0.11&mag&for&a&1K&CCD& .& • Strongly&depends&on&the&detector&type&and& .& Reset&+& the&instrument&al5tude&& .& Transfer&to&& Memory& .& memory& zone& • Cannot&be&seen&on&the&CoRoT&star&windows& .& zone& readout& T~0.2&s& T&~23&s&& • Cannot&be&seen&on&the&CoRoT&background& ! windows& ∇ Bk
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 35& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 36&
€ reminders&
• 196&sky&&background&windows&on&the&CCD&:&147&windows&@&512s,& 49&windows&@&32s& • The&&CCD&is&split&in&14*14&square&zones,&1&window&per&zone;&~&3/4& sampled&@512s&and&1/4&sampled&@&32s&(star5ng&at&SRc01)& • Several&methods&proposed&for&the&background&correc5on:& – Subtrac5on&of&the&nearest&background&window&value& – Subtrac5on&of&the&combina5on&of&the&3&nearest&background&windows& value& – Subtrac5on&of&a&sky&background&model& • The&first&two&methods&are&very&sensi5ve&to&hot&pixels&=>&subtrac5on&of&the& median&value&of&all&the&background&windows& – Small&sensi5vity&to&hot&pixels& – Same&correc5on&for&the&whole&CCD&& • OK&at&the&beginning&(no&dark¤t,&uniform&background)& • Not&OK&with&ageing&(cf.&dark¤t&and&readout&process)&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 37& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 38&
Sky&backgrouds&components&
LRa06& – The&effec5ve&sky&background& – The&satellite&environment&:&uniform&effect,&well& corrected&by&the&median&value& – The&dark¤t& • A&uniform&value&(integra5on&phase)&corrected&by&the&median& value& • Depends&on&the&posi5on&of&the&window&(Y_axis)&during&the& readout&phase& – Small&effect&at&the&beginning&of&the&mission& – The&gradient&increases&with&5me& • Depends&on&the&CCD&temperature& LRc02& • Need&to&correct&the&lightcurves&from&the&dark& current&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 39& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 40& Adopted&correc5on& Jump&correc5ons& (A.&Deru)& (effects&of&impacts)& (J_M&Almenara)& – Subtrac5on&of&a&median&sky&background&depending&on& 5me&(unchanged)&:&correc5on&of&the&real&sky&background&+& dark¤t&during&integra5on& – Subtrac5on&of&a&component&depending&on&theY&posi5on&of& the&window&:&correc5on&of&the&dark¤t&during&readout& – Dark(y)&=&α&*&y&+&Cte& • α&:&mean&of&the&slopes&at&the&beginning&and&end&of&the&run& • Cte&=&Dark(0)&–&Median_bk&(0)& • Ex&:&for&Corot_ID=223942686& – SRa01&:&y&=&409&;&Cte&=&&_13,17&e_/pix/32s&;&_1&172,21&e_/32s& – SRa05&:&y&=&196&;&Cte&=&_122,62&e_/pix/32s&;&_9&442,02&e_/32s& – To&be&compared&with&the&minimal&values&660&000&et&&690&000&e_/32s& F F 0 = c(t d) with c 0 b + e CHEOPS&Workshop&_&Madrid&_&18&june&2015& 41& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 42&
Jump&correc5ons& Gap&filling&
Jump&detec5on&coupled&with&ephemerises&of&known&phenomena& Filling&the&gap&without&changing&the&Fourier&spectrum& (planetary&transits,&binary&systems…)&for&nega5ve&jumps&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 43& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 44& Systema5cs&& Gap&filling& correc5on& 2&methods&tested&:& • _ ARMA&:&J_P&Granado&:&sliding&average&and&self& Es5ma5on&of&localised&biais&on&the&detector&with& regressive&algorithm.& 5me.& _ Inpain5ng&:&CEA&Algorithm&(R.&Garcia,&S.&Pires)& Inpain5ng&method&implemented& _&2&correc5on&steps&to&correct&mainly&SAA&crossing& and&longer&gaps.&
&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 45& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 46&
Systema5cs&& Evolu5on&of&the&PSF&size&(focus& correc5on& varia5ons&?)&
360&
• Computa5on&for&each&run&of&correc5on&coefficients& 350&
for&each&point&of&the&LC& 340& • Need&the&gap&filled&and&jump&corrected&data&to& 330& reduce&the&biases& 320& PSF$surface$(px)$
310&
300& LRa01& LRa02& LRa03& LRa04& LRa05& LRa06& LRa07& Colors&=&posi5ons&on&the&A1&CCD&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 47& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 48& Overall&increase&of&the&noise&with&5me& Overall&increase&of&the&noise&with&5me& (Aigrain&et&al.&2009)& (R.Asensio&:&Master&Thesis)& • Es5ma5on&of&the&varia5on&of&the&2h&data&(with&the&method&used&by& • Es5ma5on&of&the&varia5on&of&the&2h&data&scarer&using& Aigrain&et&al.&2009)&over&6&years& the&Median&Absolute&Devia5on&method&
&
&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 49& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 50&
Overall&increase&of&the&noise&with&5me& Conclusions& (R.Asensio&:&Master&Thesis)&
• Es5ma5on&of&the&varia5on&of&the&2h&data&scarer&for&R=14&with&5me& using&the&Median&Absolute&Devia5on&method&(used&by&Aigrain&in& • High&accuracy&photometry&is&difficult,&but¬& 2009)&using&several&CoRoT&runs&over&6&years& impossible& • Ini5al&and&inflight&calibra5ons&/&monitoring&are& mandatory.&Inves5ga5on&tools&should&be& foreseen.& • The&data&reduc5on&pipelines&role&is&crucial.&The& 5me&required&to&make&them&work&should¬&be& under_es5mated& & & • Ageing&is&real,&but&does¬&prevent&from&good& observa5ons&and&science&if&ageing&can&be& • However&:&no&observa5on&of&transmission&or&QE&loss…& monitored.&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 51& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 52& Lesson&6&:&the&force&of&a&project&is& the&force&its&team&
Corolar&lesson&:&Don’t&be& arracted&by&the&dark&side&of&the& force….(hum…&sorry,&it&is&another& story)…&
CW&11&@&IAC& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 53& CHEOPS&Workshop&_&Madrid&_&18&june&2015& 54&
Last&lesson&:&life&con5nues&aver& CoRoT&CHEOPS&
CHEOPS&Workshop&_&Madrid&_&18&june&2015& 55&