APOGEE observes the Sun

APOGEE observed its first astronomical object on Jan 17th 2011 using the full optical system of the instrument, from fibers to the CCDs. This is a major milestone for one of the largest infra-red spectrographs ever built. Soon the instrument will be shipped to Apache Point Observatory for installation and integration with the SDSS telescope; stay tuned for more data from APOGEE.

The two images below show the solar spectrum observed by APOGEE. The first is the raw data taken from the CCD detectors; the dark grey bands are four groups of 30 fibers (or spectra) each, i.e., 120 spectra of the Sun in total. The second image is a plot of the extracted, one-dimensional spectrum of the Sun showing the infrared brightness of sunlight as a function of wavelength. The data still need calibrating but the many features around 1800, 2800 and 3000 pixels (x-axis) in the spectrum are well-known absorption bands caused by methane and cardon dioxide in our atmosphere. The drops to zero in the spectrum (at 2100 and 4400 pixels) are caused by gaps between the CCD detectors and are therefore not a real features in the Sun spectrum.

Raw data from APOGEE of the Sun

Solar spectrum. First astronomical light seen by APOGEE

More photos and technical details at http://www.astro.virginia.edu/~jcw6z/firstlab/ Congratulations to the APOGEE team!

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