AI Insight
Researchers have created STARSFLUX, a comprehensive all-sky catalogue containing 64,484 calibrator star spectra covering wavelengths from 0.3 to 30 micrometers (ultraviolet to mid-infrared). The catalogue combines Gaia DR3 data, multi-band photometry, and synthetic stellar atmosphere models to provide absolutely flux-calibrated spectra and angular diameters for each star. Validation tests show the catalogue achieves accuracy of approximately 3-5 percent when compared against independent measurements from Gaia and established infrared standards.
Why it matters
Ground-based infrared astronomy is severely limited by atmospheric absorption and the scarcity of nearby calibration stars. This catalogue provides astronomers with a vastly expanded database of calibrators accessible across the entire sky, enabling more accurate flux measurements for faint astronomical sources and improving the quality of both spectroscopic and interferometric observations.
Understand the Science
arXiv:2607.11730v1 Announce Type: new
Abstract: Obtaining accurate fluxes for faint sources from the ground at near- and mid-infrared wavelengths is challenging because of rapidly varying atmospheric absorption, and is often limited by the lack of a nearby spectro-photometric calibrator. We present the STellar Absolute Reference Spectroscopic Flux Library (STARSFLUX), an all-sky catalogue of 64,484 calibrator spectra spanning 0.3–30 $mu$m, based on the Mid-infrared stellar Diameters and Fluxes compilation Catalogue (MDFC). STARSFLUX combines Gaia DR3 stellar parameters, multi-band photometry from space- and ground-based surveys, and synthetic NewEra PHOENIX atmosphere models. For each star, we fit the observed SED with an interpolated model spectrum, angular diameter, and extinction to produce an absolutely flux-calibrated spectrum. The derived angular diameters can also be used to calibrate interferometric observations. We validate the catalogue using three independent tests. First, STARSFLUX angular radii agree closely with Gaia DR3 radii, with a median $|Delta R|/R_{rm Gaia,DR3} simeq 4.8$ per cent. Second, integrated L-band (2.8–4.2 $mu$m) fluxes for 12 stars in common with the Cohen infrared standards agree with Cohen values with a mean absolute percentage difference of $4.7 pm 2.6$ per cent. Third, comparison with Gaia DR3 BP/RP spectra shows that the near-UV/visible/near-IR absolute spectro-photometric fluxes agree to approximately 3 per cent. The FITS spectra are available at https://home.strw.leidenuniv.nl/~gamez/ and will be submitted to VizieR.
Source: STARSFLUX: an all-sky catalogue of absolute spectro-photometric calibrators from 0.3 to 30 $mu$m