India’s Perspective on Exoplanet Research

Suvrath Mahadevan

on behalf of

Abhijit Chakraborty,

Physical Research Laboratory (PRL), Department of Space, India

India’s Perspective

• India is a relative newcomer to modern exoplanet research

• On going strategy

Near Term (within next 1yr)

Highly stable fiber fed spectrograph, PARAS, being commissioned at the Mt Abu 1.2m telescope in Jan 2010

Long Term (next 5-10 years) possibilities

• Dedicated 2-2.5 m robotic telescope with PARAS for precision RV followup

• Possibilities of Space Missions in very preliminary discussion stage

ChandraYaan-1 Spacecraft, India’s Moon Mission

Polar Satellites Launch Vehicle (PSLV). Payload consists of instuments built by ISRO, ESA, NASA, and some other organizations.

http://www.isro.org/chandrayaan/htmls/mission_sequence.html

PARAS

PRL Advanced Radial Velocity All Sky Search

• Fiber-Fed Spectrograph

• Built to be very stable

• Fiber fed

• Temperature stabilized, and in a vacuum enclosure

• Star and Th-Ar on different fibers, so simultaneous calibration of Instrument Drift

Star

Th-Ar

PARAS, India’s First high efficiency stable echelle spectrograph will be coupled to the Mt Abu 1.2 telescope

PARAS Team includes Abhijit Chakraborty (PI), F.M Pathan, Venkatramani, S Mahadevan (PSU), Harvey Richardson (UBC), Arpita Rao, SAC & PRL Engineers

•80 nights per year guaranteed to planet search program with PARAS

•Median site seeing is 1arcsec. PARAS fiber on sky is 2.35 arcsec- so VERY efficient instrument.

•150n/yr photometric, ~250 clear night

PARAS coupled to the Mt Abu 1.2 m telescope

Instrument Commissioning on site Jan 2010

PARAS: A stable Fiber Fed Echelle Spectrograph

PARAS: A stable Fiber Fed Echelle Spectrograph

•PARAS is a R=70k resolution Echelle spectrograph

•Comissioning Jan 2010

•Mt Abu 1.2 Telescope in India

•370-850nm simultaneous coverage

•Th-Ar Calibration

•Fiber Fed

•White Pupil Design

•Prism Cross-Diperser

Chakraborty, Richardson & Mahadevan, SPIE 2008

100 mm Beam

R4 Grating

PARAS: A stable Fiber Fed Echelle Spectrograph

370 nm

850nm

Wide Simultaneous Wavelength Coverage with a 4k x 4k deep depletion e2v CCD. CaII HK-Ca NIR Triplet coverage in one shot.

PBM8Y prism has low dn/dT (3 X 10 -6) minimizing temperature shifts

PARAS: A stable Fiber Fed Echelle Spectrograph

PARAS will be enclosed in a vacuum vessel and operated at 10-2 mbar for instrument stability.

Fully double scrambled fibers for high RV accuracy

Acknowledge very useful discussons/input from F. Pepe, S. Udry Geneva Obs.

The main Optics are expected to arrive from SESO (France) in late Nov 09.

Inside view

Prism

Vacuum Chamber

PARAS: A stable Fiber Fed Echelle Spectrograph

Prism

PARAS: A stable Fiber Fed Echelle Spectrograph

31.6g/mm R4 echelle grating in its storage cell

Camera systems from IR labs with a vibration damping system to reduce cryotiger vibration amplitude to 10nm

Prism

PARAS: A stable Fiber Fed Echelle Spectrograph

Dedicated Insulated Room has been constructed in the Mt Abu observatory to house the PARAS instrument

Insulation and active temperature control of room will maintain the instrument temperature at 0.01 deg C around the set point of 25C

Include

Telescope Focus& Pinhole position 50micron Fiber Tip

Telescope F/13 to Fiber F/4 transfer optics

F/13 Doublet F/4 Doublet

F/4 Doublet

Jacketed Fiber tip

Jacketed Fiber tip

PARAS: A stable Fiber Fed Echelle Spectrograph

Custom made fiber assembly by Polymicro has both fibers in the same epoxy with a 180um space between them. Monolithic assembly minimized drifts between the star and calib fibers.

Include

Dedicated 50cm Photometric Telescope

•Dedicated 50 cm Photometric telescope will be available at the Mt Abu site by December 2009

•Equipped with a 4k x 4k front illuminated CCD (QE=60% in V)

•FOV is 37 x 37 arcmin

•Will be useful for photometric monitoring of PARAS candidates, known transits, and wide field searches

PRL Exoplanet Programs are Supported by the Govt. of India, Department of Space, and the PRL director (J.N. Goswami)

Include

PARAS + Dedicated 50cm Photometric Telescope

Refining Ephemerids with RV and then searching transit windows to find long period TRANSITING planets around BRIGHT stars with KNOWN RV planets – see TERMS poster by Stephen Kane

Complementary photometric capability along with PARAS enables scientific programs like the search for transits around long period exoplanets by refining their transit windows with RV and then observing with the 50cm telescope , and with PARAS to detect the transit with photometry and Rossiter McLaughlin.

Also a good suite to confirm candidate exoplanets around giant stars detected with ongoing surveys like that at the HET.

PARAS red wavelengths useful to test concepts of radial velocity extraction in presence of telluric features. Essential test for future NIR spectrographs.

Possible follow-up and confirmation of candidates from ongoing multi-object RV surveys like SDSSIII MARVELS

Long term monitoring of bright stars to discover low mass exoplanets.

Stellar astrophysics studies will also be enabled.

Science with ongoing ProgramsInclude

Future Plans

•PARAS has been built to be very efficient and can be coupled to a future 2.5-3.5m telescope with very little additional slit losses

•Goal is to have a dedicated 2.5m robotic telescope for PARAS and for RV searches by 2015. Long term monitoring of bright stars ar high RV precision, followup and confirmation of long period candidates

Longer term ideas for possible space missions in very preliminary discussion stage