Exoplanet Transit Observations at Exoplanet Transit Observations at Weihai Observatory of Shandong UniversityWeihai Observatory of Shandong University

Chen CAOChen CAOcaochen@sdu.edu.cn

Weihai Observatory of Weihai Observatory of Shandong UniversityShandong University

Longitude: 122°03‘ 02“ ELatitude : 37°32‘ 12“ NAltitude : 110 m-- Observing nights: ~200/yr-- Average seeing: ~1.5”

Optics: classic Cassgerain design, 1000mm1000mm optical working diameter, Primary focal ratio:f/3, system focal ratio: f/8 FOVFOV: ~ 11’

Mount: equatorial fork mount

Maximum loading weight is 100kg at the focus flange

Maximum slew speed is 4 degrees per second in both RA and DEC axis

Pointing: 5.4 arc sec RMS for 20-90 deg altitude

Tracking: 0.54 arc sec RMS in 10 minutes blind guiding

TelescopeTelescope

Made by APM from Germany

• 2K * 2K 13.5m B.L.

• cooling with air ~ -65°

CCCCDD

PIXIS 2048BPIXIS 2048B

ACE Dual filter wheel

Photometry system—Filter system

UBVRIUBVRIuvbyuvby

MotivationMotivation• Goal AGoal A -- -- More Exoplanet transits’ data More Exoplanet transits’ data help to help to

derive higher accuracy planet parameters ; derive higher accuracy planet parameters ; discover the possible “third” object by transit discover the possible “third” object by transit timing. timing.

• Goal BGoal B -- -- Try to detect transits of those known Try to detect transits of those known exoplanets which were discovered by RV method exoplanets which were discovered by RV method but still without transit detections.but still without transit detections.

• Goal CGoal C -- -- Make follow-up photometry Make follow-up photometry observations of the new exoplanet systems observations of the new exoplanet systems discovered by our new high-res spectrograph (will discovered by our new high-res spectrograph (will be installed by the end of this year, by NIAOT).be installed by the end of this year, by NIAOT).

High-res Spectrograph High-res Spectrograph designdesign• R: 38,000~55,000 R: 38,000~55,000

• Operational Wavelength:3,800 Operational Wavelength:3,800 ÅÅ~8,800~8,800ÅÅ

• Wavelength Overlap in Echelle Wavelength Overlap in Echelle orders:3,800orders:3,800ÅÅ~7,700~7,700ÅÅ

• Echelle: Newport spectra physics R2.9 Echelle: Newport spectra physics R2.9

Lei Wang’s talk

Ephemeris – I. xls from AXAEphemeris – I. xls from AXA(for Goal A)(for Goal A)

Ephemeris – II.Ephemeris – II. (transitsearch.org)(transitsearch.org)

(for Goal B)(for Goal B)

ObservationObservationss

Instruments:Instruments:

• 1m1m reflecting telescope (by APM)

• PIPI CCD (PIXIS 2048B, 2K*2K)

Observations:Observations:

• 30 ~ 60 mins30 ~ 60 mins before and after the predicted transit time (if possible)

ObservingObserving

loglog

Total: ~3030 nights

1212 transit events

Data Data ReductionReduction• Data reduction (bias, flat subtraction etc.) with IRAFData reduction (bias, flat subtraction etc.) with IRAF

• Aperture photometryAperture photometry

using using IRAFIRAF & & MaxIM DL (by students)MaxIM DL (by students)

Send the results to:Send the results to: TRESCA TRESCA ProjectProject

http://var2.astro.cz/EN/tresca/transits.php?pozor=Chen%20CAO

TrES-3b (V=12.4, D=27.1mmag)

2009-04-16

2009-05-03

2009-06-10

2009-07-31

TrES-3b

2009-07-31

TrES-1b (V=11.8, D=25.1mmag)

XO-2b (V=11.2, D=14.2mmag)

2008-12-11

2009-04-21

2009-05-04

2009-08-30

WASP-1b (V=11.8, D=14.6mmag)

2009-08-30

WASP-2b (V=12.0, D=19.5mmag)

2009-08-01

WASP-3b (V=10.6, D=12.2mmag)

HAT-P-7b (V=10.5, D=7.07.0mmag)

2009-04-21

Research assistant: undergraduate

students

30cm refracting telescope

(with a SBIG ST-8E CCD)

F. F. WangWang

X. ZhangX. Zhang N. SongN. Song J. ZhangJ. Zhang

Next Step WorksNext Step Works

• Continuing the transit observations ;Continuing the transit observations ;

• Analyze the results in more details ;Analyze the results in more details ;

• Install our high-res. Spectrograph.Install our high-res. Spectrograph.

So we really need:So we really need:• Your good advice & suggestions !!!Your good advice & suggestions !!!

• Better exoplanet “target” !!Better exoplanet “target” !!

• Good collaborators !!! Good collaborators !!!

• More observing time !More observing time !

Welcome to Welcome to Weihai Weihai ！！

Liugong Liugong IslandIsland

Contact:Contact: caochen@sdu.edu.cncaochen@sdu.edu.cn 0631-5688881(O) 13686318965 (M)

Thank You !! 感 謝 !!