Stellar Observations Network Group (SONG): SONG in New Mexico

(updated 1/25/2024)

Major upcoming milestones:

• Finalize focal plane unit design
• Test image quality and dome seeing
• PW1000 install, January 17/18, 2024
• Receive iodine cell
• Receive echelle grating

SONG is planned as a network of eight fully-robotic 1-m telescopes that will carry out near-continuous, high-precision radial-velocity measurements of bright stars. The telescopes are to be equipped with nearly identical optical spectrographs capable of reaching a precision of 1 m/s per exposure on stars down to a visible magnitude of M_V=6. The nodes in the network are distributed in longitude to be able to continuously monitor stars and avoid the day/night cycle. The figure highlights the site locations. The large stars have operating or soon-to-be-operating nodes, and the small stars are possible future locations. The horizontal lines show nominal coverage. SONG is modeled after the the six-station Birmingham Solar Oscillations Network (BISON) and the Global Oscillation Network Group (GONG), which have both very successfully studied the Sun with helioseismology for over 25 years. SONG is a highly cost-effective and innovative next step forward for asteroseismology.

SONG was conceived and is led by collaborators in the Department of Physics and Astronomy at Aarhus University in Denmark. That group spearheaded the development of the high-precision spectrograph instrumention, which was ultimately realized at the prototype facility at the Observatorio del Teide in the Canary Islands on Tenerife, Spain. SONG-Tenerife has been operating since 2014 and consists of the Hertzsprung-SONG Telescope. A second node has recently been built at the Mt. Kent Observatory in Queensland, Australia and is undergoing commissioning as of January 2022. A third node is under construction at a new observatory in Lenghu, China, and is scheduled to be operational by 2024. As the figure demonstrates, SONG in New Mexico will be a crucial bridge for the global network, providing required longitudinal coverage to continuously monitor stars.