Las Campanas Observations: Autumnal Equinox 2017

By: David Osip, LCO Associate Director

On the date that the northern and southern hemispheres of our Earth are equally illuminated by the Sun, we celebrate the successful commissioning of the APOGEE-2S spectrograph on the Irénée du Pont 2.5m telescope at LCO.   

APOGEE 2S at Las Campanas

Left: Spectrograph housed in the recently finished clean-room environment. Right: First science spectra obtained 17/02!

While the APOGEE team in the north constructed a sister spectrograph to the one installed at Apache Point Observatory in New Mexico, team members in the south along with LCO site personnel worked over the past two years to make suitable modifications to the du Pont telescope, dome, and associated infrastructure in order to provide an able and willing host for the instrument and once again take full advantage of the extraordinary inherent wide field capabilities of the telescope.

Mosaic of work done at du Pont for APOGEE

Mosaic of images from installation and commissioning runs for APOGEE-2S at LCO. [image credit: APOGEE team]

With a telescope and spectrograph now operating in each hemisphere, the APOGEE-2 project  [http://www.sdss.org/surveys/apogee-2/ @APOGEEsurvey] is finally able to see our entire Milky Way galaxy.  Penetrating the obscuring dust even towards the centre of our galaxy, the APOGEE spectrographs use stellar spectra at near infrared wavelengths to assess the chemical and dynamical state, distribution, and evolution of populations of stars spanning the disk, bulge, and halo of the Milky Way.  Now the fun part truly begins!

 Milky Way image with du Pont telescope at bottom and Swope inverted in this panoramic reconstruction by Y. Beletsky.