Project 1640 is a high contrast imaging project at Palomar Observatory. It seeks to image

brown dwarfs Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...

and Jupiter-sized planets around nearby stars.

Rebecca Oppenheimer Rebecca Oppenheimer is an American astrophysicist and one of four curator/professors in the Department of Astrophysics at the American Museum of Natural History (AMNH) on Manhattan's Upper West Side. Oppenheimer is a comparative exoplanetary sci ...

, associate curator and chair of the Astrophysics Department at the American Museum of Natural History, is the principal investigator for the project.

Instruments

The two main instruments behind Project 1640 is an

Integral field spectrograph Integral Field Spectrographs (IFS) combine spectrographic and imaging capabilities in the optical or infrared wavelength domains -from 0.32 μm to 24 μm- to get from a single exposure spatially resolved spectra in a bi-dimensional region. Develop ...

(IFS) and an Apodized-pupil Lyot

coronagraph A coronagraph is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star's bright glare – can be resolved. Most coronagraphs are intended to view t ...

at the

Hale Telescope The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, de ...

at Palomar. This instrument is the basis of a high-contrast imaging long-term observational program. The instrument uses the chromatic nature of the

speckle noise Speckle, speckle pattern, or speckle noise is a granular noise texture degrading the quality as a consequence of interference among wavefronts in coherent imaging systems, such as radar, synthetic aperture radar (SAR), medical ultrasound and op ...

to distinguish it from any true astrophysical companions, including software which increases sensitivity by 10-20 times. Such sensitivity can detect planets of several

Jupiter masses Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is b ...

. The spectrograph obtains 23 images across the J and H bands (1.06-1.78 µm), with a spectral resolution of 45. In approximately 2013, a Post-coronagraph Wave Front Calibration System was added. Its goal is to achieve a wave front irregularity of less than 10 nm.

Preliminary results

On March 10, 2013, Project 1640 made its first remote imaging of another solar system. It imaged four red exoplanets orbiting the star HR8799, 128 light years away from Earth, determining the spectra for all four. One significant result was the detection of a chemical abnormality. At normal temperatures, such as those surrounding the four exoplanets,

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...

and

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...

should both be present in significant amounts. However, the exoplanets have either

in abundance, while the other chemical is missing. Other chemicals such as acetylene (not previously detected on any exoplanet) may also be present. There is also a significant cloud cover on the planets.

References

Astronomical imaging Exoplanet search projects Infrared spectroscopy Palomar Observatory {{astrobiology-stub