The photometric instruments in space (most, corot)are going to open new insights on the knowledge of stellar interiors. However,ground-based asteroseismic observations remain justified as they can bring complementary velocity measurements, and allow the study of much more targets. A competitive instrument must make it possible the observation of a representative set of solar-like starswith magnitude down to 5, and a velocity precision as low as a few cm s-1 after 5 nights behind a 2-m class telescope. The siamois project based on a Fourier interferometer has emerged as asuitable solution to fulfil the specifications for a ground-basedasteroseismic network. The photon noise limitedperformances have been examined and compared to those of a gratingspectrometer (Mosser et al.  2003) showingthat this type of instrument can reach the required specifications. With a design based on a monolithic interferometer, with a compactinstrument easy to set up, to operate remotely with a limited data-flow, it can fit well the harsh conditions of Dome C. Main advantage, a single unit is needed due to the circumpolar position of the targets for the Doppler detection of stellaroscillations on solar-type stars.As a test bed, siamois could be put on 0.8-m class telescope like irait (Busso et al.   these proceedings).

We present a short synthetic summary of prospects for stellar astrophysicsfrom Dome C. We conclude that a progressive strategy could be defined, givingaccess to a 2 m-class telescope, equipped with a highly efficient optical/infrared spectrograph/spectropolarimeter and a wide-field infrared imager, in the 2008 timeframe, then evolving toward a larger telescope with integral field spectroscopic capabilities, and finally to more ambitious instruments, such as interferometers.

The atmosphere above the Concordia station at Dome C Antarctica offers unique advantages to infrared interferometry. No other astronomical technique experiences comparable performance gains relative to other good sites. The dramatic improvement in infrared interferometry performance at the Dome C site enables a relatively modest instrument, based on three ${\sim}2$ m class telescopes, to be capable of extensive unique discovery space science; such an instrument would be especially well-suited to the study of extrasolar planets. The conditions at Concordia are the closest Earth analog to those of space and potentially provide a stepping stone to proposed space interferometers, such as Darwin and TPFI, that will search for biomarkers on other habitable worlds – worlds that may well have been detected initially by an infrared interferometer operating at Dome C.


We study the potential impact of a photometric search for transiting exoplanets from Dome C. In the past year, four new transiting exoplanets have been found by ground-based surveys, including three detected by our follow-up of OGLE transit candidates with FLAMES/UVES on the VLT. Based on the experience of this survey, we have built a simulation to predict the expected number of transiting exoplanet detections from photometric searches. We apply these simulations to a possible survey based at Concordia. We find that the Antarctica location solves the two main limitations of ground-based transit surveys: the diurnal-cycle time sampling, and the hour-timescale systematic photometric variations. The expected numbers of detections are much larger than for other ground-based surveys. They show the high potential of such projects at Dome C, even with a small telescope.

We describe the scientific rationale and the preliminary optomechanical design for a 2 m class telescope designed to achieve ground layer correction over a ≈15 arcmin Field of View (FoV) to be located at the Dome-C site. The proposed science case is the detection of microlensing events in and by globular clusters and nearby galaxies that, for a high probability of success, requires exceptional seeing (≈0.2 arcsec or better) and a large target density (the centre of a globular cluster with a corresponding telescope FoV of ≈15 arcmin). This approach can capitalise on some of the unique qualities already observed above the Dome-C site, namely that the atmospheric turbulence is largely limited to a ground layer of small thickness only, a relatively low Greenwood frequency and uniterrupted sky coverage during the winter months for objects such as the globular cluster 47-Tuc. Further to the central science case of microlensing the telescope could provide a technological testbed for future telescopes and, given the unique atmospheric properties witnessed already during previous site testing compaigns, has the chance to provide a large amount of data (based on accurate and continuous light curves lasting several months) for fields of research outside that of microlensing. Details of the specific concepts of adaptive optics to be adopted for this telescope are outlined.

The study of extra-solar planets currently motivates a number of large scale observation programs, and also new developments for dedicated instruments. Such programs involve a wide range of observational techniques, from either space-based or ground-based telescopes, including high contrast imaging, photometry, spectroscopy or interferometry. After a brief overview, we discuss here if, how and for which part, the specificities of the Dome C site can significantly contribute to this general observation strategy.

Studies of the transparency of the atmosphere and weatherconditions clearly reveal that the site of the Dome C couldbecome in the next decades one of the best terrestrial sites forastronomy, from millimeter to optical wavelengths. In thisarticle, we review the potentiality of the site for studiesdedicated to planetology.

The Concordia Station (Candidi 2003), on the AntarcticaPlateau, will soon become one of the best observatories to performinfrared observations in the 2–20 μm atmospheric windows andbeyond, thanks to its low sky background, low temperature andhigh atmospheric transparency. The possibility of passivelycooling the telescope is a further advantage. We describe herethe first permanent Antarctic infrared telescope, underdevelopment for the Dome C base. It is the InternationalRobotic Antarctic Infrared Telescope (IRAIT). We briefly outlinea few scientific motivations for it, then we review the technicalcharacteristics and the status of its development. The infraredcamera for IRAIT is described in another dedicated paper in thisvolume.

In the study of extended sources such as star forming regions, galactic planetary nebulae or comets wide field integral-field spectroscopy at high spectral resolution in the infrared, would be the ideal tool. It is shown that an imaging FTS (IFTS) is the only instrument which can combine a wide field, up to ~10', with a spectral resolution ≥105. At Dome C, in the 2 to 25 μm region, as instrument of a 3-m class telescope, a wide-field IFTS would have no equivalent in space and on ground. It can take full advantage of all the astronomical properties of this site, in particular the lowest thermal background emission conditions on Earth. A program to simulate the expected performances has been developed. At the highest resolution the best sensitivity implies the use of narrow-band filters on the emission lines of interest.

Dome C CONCORDIA offers very low infrared sky background conditions well suited to broad-band imaging surveys beyond 2.3 μm. I briefly describe the scientific interest of extending the recent 2 μm surveys in this spectal range, and the main lines of a project that would eventually lead to a large facility aimed at high angular resolution imaging and spectro-imaging (AMIDST project), with a first step dedicated to monitoring the IR sky background emission (AIRBUS experiment).


We present the Far Infrared Telescope project submitted to the micro satellite programme of CNES and initially combined to a γ raymission. Millimeter wave emission from MeV-electrons is now wellknown, and on very few occasions non solar dedicated γ raydetectors have revealed emission from electrons at still higherenergies. The combination of two diagnostics: relativisticelectrons-synchrotron radiation in the far infrared and Bremsstrahlungat γ ray would probe electrons at energies above 10 MeV with100 ms time resolution, yielding unique information on the yet unknownhigh energy cut-off of the electron spectrum, and on the responseof the high photosphere to energy input during flares. We emphasizethe opportunity to observe solar flares in far infrared bands andto test uncooled detectors at the ground based station dome C in Antarctica.


We propose a science demonstration experiment for antarctic stellar interferometry, dedicated to the goal of obtaining the first low-resolution spectra in the thermal infrared of a few “hot Jupiter” type exoplanets. It would provide a unique platform to acquire operational experience, and build up an extensive database on the relevant site properties at Dome C, as a preparation for a more ambitious facility.

This paper describes a coronagraphic nulling interferometer calledKEOPS (Kiloparsec Explorer for Optical Planet Search) to be placedon the Dome C plateau of Antarctica. KEOPS is an interferometricarray of 39 1 m–2 m telescopes spread over kilometric baselines andoperated in the thermal IR region. It could search and characterizeall potential exoEarths within the 1 kpc diameter region observablefrom Dome C. We argue that even in the very difficult operationconditions of Antarctica, such a facility can compete at a muchlower cost with the non-zero risk space missions, both for for ExPNssearch and their spectroscopic characterization plus sub-massnap-shot imaging of galactic and extra-galactic compact sources.

Due to the typical high atmospheric noise and low transparency, submillimeter observations can be carried out only from sites with very high atmospheric stability and very low precipitable water vapour content. The Antarctic Plateau is important because of its remarkable atmospheric transparency and stability. Logistical difficulties have limited till now the exploitation of the unprecendented potential of Antarctica as a site for submillimeter observations. The opening of Concordia Station at Dome C is now offering to the international astronomical community a unique opportunity to perform ground-breaking astronomical science. The proposal from our multi-national group represents a first step toward the realization of an international Antarctic Submillimeter Observatory (ASO) based on a telescope with a large collecting area (12 m diameter) to carry out both continuum and spectral line observations, particularly in the 200 and 225 μm atmospheric windows and possibly also in the Mid InfraRed at wavelengths ≳40 μm.

We present wind and temperature profiles at Dome C measured during thepolar summer by balloon born sonds. Data from 197 flights have beenprocessed for 4 campaigns between 2000 and 2004. We show theexceptionnal wind conditions at Dome C: averaged ground wind speed is 3.6 m s-1. We noticed in mid-november the presence of high altitude strong winds (40 m s-1) probably due to the polar vortex which disappear in summer. These winds seem to have no effect on seeing measurements made with a DIMM at the same period. Temperature profiles exhibit a minimum at height 5500 m (over the snow surface) that defines the tropopause. Surface layer temperature profile has negative gradient in the first 50 m above ground in the afternoon and a strong inversion layer (5°C over 50 m) around midnight. Wind profiles are compared with other astronomical sites, and with a meteorological model from Meteo France.

CASPER (Concordia Atmospheric SPectroscopy of Emitted Radiation)is a spectrometer proposed for installation at Dome C, devoted tomeasurements of atmospheric emission in the spectral regionbetween 180 μm and 3 mm (3–55 cm-1). Thisinstrument will be able to perform continuous spectral sampling atdifferent altitudes at angular scales of ~1°. From therecorded data it is possible to extract atmospheric transmittancewithin 1% in the whole wide operating band, together with watervapour content and O2 and O3 concentrations. CASPER willallow us to characterize the site for future FIR/mm telescopes.Atmospheric data recorded by CASPER will allow for correction ofastrophysical and cosmological observations without the need fortelescope-specific procedures and further loss of observation timewith more precision in the observations themselves. Calibration ofground-based telescopes on known sky sources is strongly affectedby atmospheric absorption. CASPER has this as its primary goal.The spectrometer is based on a Martin-Puplett interferometer. Twodata sampling solutions will be performed: phase modulation &fast scan strategy. Sky radiation is collected towards theinterferometer by an optical setup that allows the field of view,to explore the full 0° ÷ 90° range of elevation angles. Witha low spurious polarization instrument, monitoring of polarizedatmospheric contribution will be possible.

A radiometer based on SIS mixers for astrophysical observations isbeing assembled. The system, cooled to cryogenic temperature by apulse tube refrigerator, is intended for operation on the AntarticPlateau during the local winter, using the mm dishes availablethere in the future. The system prototype will be tested at thefocus of the 2.6 m MITO telescope at the Testa Grigia Observatoryon the italian Alps. We discuss the system characteristics and theobservational programs.

The ClOVER instrument (described elsewhere in this volume) isbeing built to measure the B-mode polarisation of the Cosmic MicrowaveBackground. Each of the 256 pixels is made up a pseudo-correlationreceiver that can be realised using either waveguide or microstriptechnology. In this work we present a design study for a possiblewaveguide-based solution. Each of the individual components has beenoptimised using electromagnetic finite-element modelling software(HFSS).

We present a new, fully-funded ground-based instrument designed to measurethe B-mode polarization of the Cosmic Microwave Background (CMB). The conceptis based on three independent sub-systems operating at 90, 150 and 220 GHz,each comprising a telescope and a focal plane of horn-coupled background-limited bolometers. This highly-sensitive experiment, planned to be based at Dome C station in Antarctica, is optimised to produce very low systematiceffects. It will allow the detection of the CMB polarization over angular multipoles 20<l<1000accurately enough to measure the B-mode signature from gravitationalwaves to a lensing-confusion-limited tensor-to-scalar ratio r ~ 0.005.

The BaR-SPOrt (Balloon-Borne Radiometers for SkyPolarizationObservations) experiment, a program of the AgenziaSpazialeItaliana (ASI) co-funded by PNRA (Progetto Nazionale di Ricerca inAntartide) was originally designed as a payload for long durationballoons flights. The changing scenario, both scientific andstrategic, has led us to propose it for the starting wintercampaign of at the Concordia Base. Here the instrument and thefeatures making it suitable to operate at Dome-C are described.After the initial setup, BaR-SPOrt should not require any kind ofroutine intervention by a dedicated base staff. The experimentwill just need electrical power (less than 2 kW) and a suitableaccommodation on the field. It can be fully monitored andcontrolled, including the data acquisition, through its owntelemetry/telecommand link using IRIDIUM modems. Both the receiverand the critical electronics are housed inside atemperature-controlled vacuum chamber, providing the properlystabilized environment. The cold part of the radiometer employs aclosed loop mechanical cryo-cooler that provides temperatures <70 ± 0.1 K with low power consumption (<200 W).