GPI 3rd commissioning run — Astrometric calibration with a little help from MagAO

Astrometric calibration is critical for GPI: When we see a faint dot near a star, the best way to check whether it is a planet orbiting that star, versus whether it is a background star along the same line-of-sight, is to compare the astrometry at a later date. Astrometry means measuring the stars — measuring the exact position in arcseconds and angle from North. But to figure out the size of our pixels on the sky, and the orientation of our camera and which way is North, we have to observe known groups of stars and measure their separations and angles. Then we compare our measurements to those from other instruments and tie that back to basic calibrations done in the lab with pinhole masks to create a common reference frame. This is how we calibrate astrometry.

A handful of faint stars clustered around a bright guide star makes for an excellent astrometric calibration field. These are images of the same field with MagAO/VisAO in z’, MagAO/Clio in H-band, and GPI in H-band. VisAO images courtesy Jared Males, Clio images courtesy KM, and GPI images courtesy Jason Wang.

But the field of view of GPI is very small, and it is hard to find a group of stars that are very close together, that also have a bright enough guide star for the AO system.

Tour of the Telescope

Yesterday, we had a chance to see the telescope in all of its glory. And it is HUGE! It really makes you appreciate the amount of equipment you need to directly image these faint extrasolar planets that are orbiting other stars. Andrew, the telescope operator, then pointed the telescope down so that we could get

GPI 3rd Commissioning Run – Introduction

Hello GPI fans – this is my first post at Cosmic Diary. I’m a NASA Sagan postdoctoral fellow at the University of Arizona and a member of the Gemini Planet Imager science team. While I was at UC-Santa Cruz for my PhD, I worked with the PI, Bruce Macintosh, to develop MEMS deformable mirrors for GPI. These days, I spend a lot of time in Chile commissioning extreme AO systems, which is pretty fun! Specifically, I’m usually working on and blogging about the Magellan AO system, MagAO.

Sunset at Gemini

But this week, I’ve come down to Chile to help with GPI’s 3rd commissioning run. I’m excited to be here and to see GPI on sky!

Characterizing the exoplanet HD 95086b with GPI.

Another week and yet another article based on GPI data has been accepted for publication. A team led by a European astronomer has analyzed observations of the planetary system named HD 95086, which has been known since last year for hosting an exoplanet, named HD 95086b. GPI data was extremely useful in confirming that the planet is co-moving with its star and in constraining its properties, such as its temperature and composition.

HandK1_GPI
Final images of the HD 95086 system at H (top) and K1
(bottom) bands from two different data analysis pipelines. The planet (arrow)
is detected in all images.

The orbit of the exoplanet Beta Pictoris b – The first peer-reviewed article with GPI

Following our very successful first light observing runs in late 2013, the first publication based on Gemini Planet Imager observations is now complete!  It has been accepted for publication in the Proceedings of the National Academy of Sciencesas part of a special issue on exoplanets, and is now available on Astro-ph. We report in this publication the performance of the Gemini Planet Imager based on the first light tests. The first scientific result demonstrates that right from the start, GPI has been performing well enough to yield new insights into exoplanets: Our astrometric observations from November 2013  gave us important new information on the orbit of the planet Beta Pictoris b.

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Peering at Planets

Astronomers and engineers recently completed building the Gemini Planet Imager (GPI) to study distant solar systems. GPI will obtain high-resolution images of extrasolar planets by blocking the light of stars and detecting the faint thermal glow of orbiting planets.

Near-infrared image of Beta Pictoris b, an extrasolar planet approximately 60 light years away. The light of the host star, Beta Pictoris, is blocked in this image to reveal the much fainter light of the planet. Image processing by Christian Marois, NRC Canada.

GPI Technology: Gemini Planet Imager Adaptive Optics uses Boston Micromachines MEMS deformable mirror

Adapted from Boston Micromachines Corporation press release CAMBRIDGE, MA–(Marketwired – Feb 3, 2014) –

Boston Micromachines Corporation (BMC), a leading provider of MEMS-based deformable mirror (DM) products, adaptive optics (AO) systems and scientific instruments, announced on Feb. 3 2014 that its 4K-DM is currently installed and is being used in the Gemini Planet Imager (GPI). Deployed on one of the world’s largest telescopes, the 8-meter Gemini South telescope located in the Chilean Andes, GPI is a scientific instrument which detects light from extrasolar planets.

4k-dm (1)
The Boston 4K-DM made of a continuous surface, with 4092 actuators and a stroke of 3.5 μm. (Boston Micromachine)

Meeting the Team: GPI Science Meeting November 2013

The Gemini Planet Imager (GPI) team held our latest science meeting November 1-2, 2013, right before GPI saw first starlight. The meeting was hosted by the SETI Institute at their office in Mountain View, CA (for those curious, I did not find any signs of aliens there). Continuing with tradition, we took a group picture of the GPI team. You can tell it has grown significantly from the past.

Group picture taken at the GPI Science Meeting in November 2013.
Group picture taken at the GPI Science Meeting in November 2013.

The Next Step in Exoplanetary Science: Imaging New Worlds

In 2003, I was lucky enough to be part of a small group of astronomers that met at the University of California at Berkeley to brainstorm on an innovative idea: the design of an instrument to image and characterize planets around other stars, called exoplanets, using a telescope in the 8 – 10 meter class. A decade later, such an instrument became reality with the arrival of the Gemini Planet Imager (called also GPI, or “Gee-pie”) instrument at the Gemini South telescope in Chile.

Five known planetary systems imaged with current adaptive optics systems. Fomalhaut shown on the top-right is the only system detected with the Hubble Space Telescope. HR8799 discovery was announced in a Science article in 2008 by a team led by C. Marois including members of the GPI team (credit: C. Marois).
Five known planetary systems imaged with current adaptive optics systems. Fomalhaut shown on the top-right is the only system detected with the Hubble Space Telescope. HR8799 discovery was announced in a Science article in 2008 by a team led by C. Marois including members of the GPI team (credit: C. Marois).

Gemini Planet Imager Begins On-sky Integration at Gemini South

Adapted from Gemini Observatory e-Newscast #53

Gemini’s powerful new instrument for studying planets beyond the Solar System, the Gemini Planet Imager (GPI), has successfully received its first starlight for engineering and testing on the night of November 11-12. On-sky observations are currently ongoing for technical integration with the Gemini South telescope. The GPI team (Figure 1) began the 7-night observing run began with a head start, since preliminary pupil and pointing alignments were completed early, due to extensive preparatory work and smooth integration since the instrument arrived at Gemini South in August.

Figure 1. The GPI commissioning team at the Gemini South control room assembles for the first night of commissioning on November 11, 2013. From left to right: Naru Sadakuni, Andrew Cardwell, Marshall Perrin, Stephen Goodsell, Fredrik Rantakyro, Bruce Macintosh, Jeff Chilcote, Dave Palmer, Dmitry Savransky, Sandrine Thomas, Les Saddlemyer, Jennifer Dunn, Ramon Galvez, Carlos Quiroz, Markus Hartung. Not shown, working from the La Serena Base Facility: Kayla Hardie, Pascale Hibon, Andrew Serio, and Cristian Urrutia.
Figure 1. The GPI commissioning team at the Gemini South control room assembles for the first night of commissioning on November 11, 2013. From left to right: Naru Sadakuni, Andrew Cardwell, Marshall Perrin, Stephen Goodsell, Fredrik Rantakyro, Bruce Macintosh, Jeff Chilcote, Dave Palmer, Dmitry Savransky, Sandrine Thomas, Les Saddlemyer, Jennifer Dunn, Ramon Galvez, Carlos Quiroz, Markus Hartung. Not shown, working from the La Serena Base Facility: Kayla Hardie, Pascale Hibon, Andrew Serio, and Cristian Urrutia.