Dome C Site Characterization in 2006 with Single-Star SCIDAR

Abstract

We present observations made in 2006 with the single-star SCIDAR (SSS) at Dome C in Antarctica, allowing us to determine optical turbulence C 2 N ðhÞ and velocity VðhÞ profiles from ice levels up to about 25 km above sea level (a.s.l.). SSS is a 16 inch telescope placed on an equatorial mount that continuously tracks the Canopus star. About 90,000 individual profiles are analyzed from March to September, where surface-layer contribution to seeing can be separated from the rest of the atmosphere. Medians of high angular resolution parameters relevant to astronomy are statistically studied, such as seeing (1.0′′), isoplanatic angle (6.9′′), and wavefront coherence time (3.4 ms). For a telescope placed above the turbulent surface layer, superb conditions are encountered (medians of seeing better than 0.3′′, isoplanatic angle better than 6.9′′, and coherence time larger than 10 ms). Astronomical conditions are twice as good at the beginning of the night, with ε 0 ≈ 0:5 00 , θ 0 ≈ 11:5 00 , and τ 0 ≈ 15 ms. SSS wind-velocity profiles are consistent with National Oceanic and Atmospheric Administration analysis up to 17 km (a.s.l.), within a AE2 m s À1 error bar. Coherence étendue (which is a combination of ε 0 , θ 0 , and τ 0 ), well adapted to adaptive optics performances, is likely 4 times better at Dome C than at the already-known observatories such as Mauna Kea or ORM.

Pulsating star research from Antarctica

“…Several factors allow such good astronomical conditions such as the high altitude 3300 m a.s.l., the extremely low temperature oscillating between −50 and −83 • Celsius, the low cloudiness and air-glow emission, the extremely low light pollution and the very pure air. We clearly demonstrated that most of the optical turbulence is concentrated within the first 30 m of the atmosphere ( [10]), and the rest of the atmosphere is very quiet with a seeing of about 0.3 − 0.4 arcsec, as early noticed by [11]. Dome C lies within the best astronomical places in the world.…”

Optical Sky Brightness and Transparency during the Winter Season at Dome A Antarctica from the Gattini-All-Sky Camera

“…Good average optical seeing above the boundary layer can be obtained at the south pole, i.e., 0 37 at l = Å 2000 at 17−27 m above the ground (Marks et al 1996), and 0 23 at l m = 2.4 m (Marks 2002). At Dome C, Lawrence et al (2004) found seeing of 0 27, while Agabi et al (2006) determined 0 36±0 19, Aristidi et al (2009) found 0 36, and Giordano et al (2012) found <0 3 at ∼30 m above the ground. See also Vernin et al (2009) and Aristidi et al (2015).…”

Variable Stars Observed in the Galactic Disk by AST3-1 from Dome A, Antarctica

“…The Antarctic plateau offers a number of unique advantages for precision, ground-based, time-domain as-tronomy, such as the ability to observe continuously during winter, low scintillation noise, excellent seeing above a very low boundary layer, low airmass variations, low aerosols, low water vapor, more stable atmospheric transmission, wider wavelength windows, and a dark sky in the infrared (Lawrence et al 2004(Lawrence et al , 2006(Lawrence et al , 2008Moore et al 2008;Kulesa et al 2008;Aristidi et al 2009;Burton 2010;Zou et al 2010;Yang et al 2010;Sims et al 2010;Bonner et al 2010;Lascaux et al 2011;Tremblin et al 2011;Pei et al 2011Pei et al , 2012Sims et al 2012a,b;Giordano et al 2012;Storey 2013;Hu et al 2014;Ashley 2013;Yang et al 2016). There is thus considerable interest in overcoming the technical challenges of operating in Antarctica, so that the advantages for astronomy can be realized (Tothill et al 2008;Kulesa et al 2008;Crouzet et al 2010;Chapellier et al 2016;Mékarnia et al 2016).…”