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suppression of light from the central star. Fourth,

The NICI Planet-finding Campaign is designed to

NICI employs an additional observing technique

address three key science questions:

known as roll subtraction, a.k.a. angular differential What are the mass and separation distributions

imaging (ADI), to remove the time-variable PSF. In

ADI observations, the Cassegrain image rotator is

of planets in the outer regions (5 to 10 AU) of

fixed, allowing the image of the planet to rotate in

other planetary systems?

the field-of-view while keeping the diffraction pattern What is the dependence of planet frequency

of the PSF fixed and stable so it can be subtracted

away very accurately. Subsets of these methods have

on stellar host mass?

been used individually with previous AO imaging What are the spectral properties of extrasolar

surveys on other telescopes but NICI is the first

instrument to combine all these techniques into a

planets?

single instrument. In order to answer these questions, the NICI

The Gemini NICI Planet Finding Campaign

campaign is being carried out by a strong, multidisciplinary, international team, including leading instrumentalists, observers, and theorists drawn

NICI provides a powerful new capability for direct

from across the Gemini community. I (Michael Liu)

imaging searches and the characterization of exoplanets.

serve as the campaign’s PI, with Mark Chun (IfA/

To take full advantage of this new opportunity, our

Hawai‘i) and Laird Close (Arizona) as the primary

team is carrying out a major observing campaign with

co-investigators. The team also includes Adam Burrows (Princeton); Doug Toomey (Mauna Kea

Figure 3.

Infrared); Christ Ftaclas, Zahed Wahhaj, and Beth

NICI during a daytime check in January 2009.

Biller (IfA/UH); Neill Reid (Space Telescope Science Institute);

Evgenya

Shkolnik

(DTM/Carneigie);

Niranjan Thatte, Matthias Tecza, and Fraser Clarke (Oxford University); Harvey Richer (University of

British

Columbia);

Jane

Gregorio-Hetem,

Elisabete De Gouveia Dal Pino, and Sylvia Alencar (Universidad de São Paolo); Pawel Artymowicz (University of Toronto); Doug Lin (University of California-Santa Cruz), Shigeru Ida (Tokyo Institute of Technology); Alan Boss (DTM/Carnegie), Mark NICI amounting to up to 500 hours of observing time

Kuchner (NASA Goddard), Chris Tinney (Anglo-

over the next two years. This is the first such large

Australian Observatory); and Tom Hayward, and

campaign being carried out by the Gemini Observatory;

Markus Hartung (Gemini Observatory).

accordingly, the NICI program is also intended to serve as a model for even larger Gemini observing

The Survey

projects carried out with future instruments. To achieve the project goals, the NICI campaign The NICI Planet-Finding Campaign assembles a large-

team will target a sample of about 300 stars in the

scale coherent science program with a unified set of

extended solar neighborhood. Young stars are a

goals, observing methods, and data analysis techniques.

high priority, since planets are expected to be more

While campaign-style science is new to Gemini, large

luminous in their youth. We also prioritize stars

observing programs have been carried out in a number

having compelling indirect evidence of planetary

of fields with other major observatories, such as the

companions. The campaign sample spans a wide

Hubble Space Telescope and the European Southern

range of spectral types (i.e., stellar mass), which

Observatory’s Very Large Telescope.

is made possible by the good sensitivity of NICI’s curvature AO system for optically faint targets.

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GeminiFocus

Issue 38 - June 2009  

GeminiFocus

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