CW5 Berlin 12/2003

COROT planet field observations at INT La Palma

H.J. Deeg1, M. Deleuil2, C. Moutou2

1IAC, Tenerife; 2LAM Marseille

- Observations taken at 2.5m INT, Obsv. Roque Muchachos of the IAC

- Wide Field Camera (WFC), with 4 CCDs, 33x33 arcmin total f.o.v.

- all fields observed complete in 4 filters: B,V, r’, i’.

U filter added for some pointings in latest observations (6-9 June 2003)

- reduction performed in collaboration Cambridge - LAM - IAC

- aim: creation of photometric catalog that aids to:

- select prime target fields (in conjuction with AS, of course...)

- select pointing within target field

- select stars to be included in observed sample

CW5 Berlin 12/2003

2.5m INT, La Palma, 2486m

CW5 Berlin 12/2003

Schematics of the pointings

COROT AS-target star

CW5 Berlin 12/2003

The CCD mosaic of the WFCOverlap of ‘A’ and ‘B’ pointingsexposure times: 10-120 sec

'A' and 'B' pointings are taken in all 4 filters

CW5 Berlin 12/2003

The reduction pipeline-at Univ of Cambridge, with Wide FieldsSurvey (WFS) pipeline:

- identification of stars on images

- extraction of photometry in several aperture sizes

- generation of average nightly photometric coefficients

- production of files with stellar ADU values, one for each colors and pointings

-at LAM:

- first quality check (evaluation of seeing, selection of basic aperture size)

- application of photometric calibration from WFS,

- cross-identification of stars in different colors

- merging into one file per pointing

-at IAC:

- final photometric calibration (Feb03 data only)

- cross-identification of stars in adjacent or multiple pointings

- merging of pointings into single catalog

- second quality check (magnitude offsets across pointings)

- submission to ExoDat

CW5 Berlin 12/2003

mosaicing for a field (HD174866 field shown)

dark-redNobs=1

redNobs=2

whiteNobs ≥3

Number of 4-color observationsper star vary from 1 to 4

CW5 Berlin 12/2003

The Status of COROT field observationsGalactic center: (June 2002, photometric)HD171834 - N6633 field : 19deg2, 2.16 x 106 stars , in exodatHD174866: 8deg2, 1.48 x 106 stars, in exodat

Galactic anticenter: (Feb. 2003, seeing/extinction very variable)HD49933: 20deg2, 0.48 x 106 stars, in exodatHD57006: 1.5deg2, in exodat

Galactic center: (June 2003, photometric, currently reduced at Cambridge), included some (time-consuming) U band observationsHD171834: 6deg2 additional (1.5 deg2 in U)HD177552: 5.5deg2 (all in U too)HD175726: 7.5deg2 (with few pointings in U)

Galactic anticenter: 9 nights allocated Dec - Jan 03/04Galactic center: Summer 04, 6 nights conceded

CW5 Berlin 12/2003

The HD174866 field is fairly homogenous

i < 16 AND V-i < 1.0

For a descripion of spectral classification method, see Moutou et al.

i < 16 AND V-i >1.0

i

V-i

MSMS

Giants

CW5 Berlin 12/2003

NGC6633- HD17834 field

i < 16, all colors

i < 16 AND V-i >1.5 (red)

i < 16 AND V-i <1.0 (blue)

strong inhomogeneities,clear extinction gradient

high extinction,somewhat lower density in totalvery few backgroundgiants, dwarfs are redder

CW5 Berlin 12/2003

NGC6633 - HD171834 field; HR diagrams

zone 1

zone 3

zone 2

zone 1

zone 2 zone 3

i < 16 AND V-I < 1.0

idea: we need to define a floatingV-i (as a fct of V) segregation value toseparate dwarf vs giant pops. couldbe defined as 15% line +0.3 in V-I. Or search for minimum in histogram V-I at different mags. -> program to create maps of densities dwarfs and giants

CW5 Berlin 12/2003

HD49933 fieldi < 16

Observations taken in feb 03 with strongly varying extinction and seeing up to 5”

Photometry based on nightly zero-points (from WFS pipeline) is shown.

Some pointings are clearly suffering strong extinction

Re-calibration based on observed Landolt fields was performed

CW5 Berlin 12/2003

Photometric calibration of Feb 03 data

mag

WF

S -

mag

cat

Based on average offset magWFS

-magcat

[+color terms] of 30 Landolt-stars in L98 -> linear interpolation of zero-pt offsets applied to COROT field pointings

lastly: Re-assembly of merged catalog: verifiy that each pointing added does not have offset >0.1mag in any color of overlapping stars

relatively good conditions in short windows in 3rd night: |mag

WFS-mag

cat| <~

0.02mag

-> WFS calibration should be fine at photometric conditions?needs verification

CW5 Berlin 12/2003

before and after final phot. calibrationHD49933 fld, mag i < 16

CW5 Berlin 12/2003

histograms against Vmag

HD49933 aftercalibr, 20°2, 0,43M *

HD174866/N663319°2, 2.15M *

Nst

ar

HD174866, 8°2, 1,48M *

CW5 Berlin 12/2003

Summary

Galactic center: Fields HD174866, HD171834 +NGC6633 are nearly complete and calibrated photometry has been inserted into COROT source catalogue.

In four photometric nights (June 6-9, 2003) large parts of the new target fields HD175726 and HD177552 were observed, with reduction in progress. Six nights at INT/WFC conceded for summer 04.

Galactic anticenter:Field HD49933 is mostly completeHD57006 only started.10 nights at INT/WFC conceded for Dec 03/Jan 04.