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Transneptunian Automated Occultation Survey (TAOS II)

TAOS II Website

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Lightcurves of an occultation of a background star by Pluto observed on 15 Aug. 2018 at OAN, SPM in Baja California, México. The lightcurves were collected at a cadence of 20 Hz using two of the TAOS II telescopes, one with a commercial Andor Zyla CMOS camera (grey) and one with the TAOS II prototype CIS107 CMOS camera (blue). The spikes in the middle of occultation event, which are consistent in both light curves, are scintillation events stemming from density waves in the atmosphere of Pluto.

Pluto Occultation 2018

The installation of the TAOS II telescopes was completed in 2017 October. This image of the galaxy M100 is the first image we acquired with one of the three new telescopes.

First Image from TAOS II Telescopes

Installation of TAOS II Dome

Assembly of TAOS II Dome

Installation of First TAOS II Telescope.

TAOS II enclosures at San Pedro Mártir Observatory

TAOS II Telescope.

TAOS II Enclosure at San Pedro Mártir Observatory

Installation of TAOS II Primary Mirror

Preparing to coat one of the TAOS II primary mirros at San Pedro Mártir Observatory. Mirror is installed in the coating chamber.

TAOS II Primary Mirror Coating

Rear view of the three TAOS II telescopes being assembled at DFM Engineering, in Longmont, Colorado, USA.

Rear View of the TAOS II Telescopes

Conceptual design of the TAOS II CMOS cameras.

TAOS II Telescopes

TAOS II Groundbreaking Ceremony.

Cross sectional view of the TAOS II CMOS camera design

The Transneptunian Automated Occultation Survey (TAOS II), will measure the size distribution of small (diameter 300 m < D 30 km) Trans-Neptunian Objects (TNOs). The TNO size distribution is of scientific interest because it provides important information on the formation and dynamical evolution of the Solar System. Furthermore, the Trans-Neptunian region is the source of the short period comets, and an accurate census of these small objects can help us understand the mechanism by which TNOs are perturbed into cometary orbits. Such objects are impossible to detect directly because they are too faint to be seen with even the largest telescopes. However, when such an object passes in front of a star, the star will "blink out" for a small fraction of a second. The detection and characterization of these occultation events are the primary science goals of this survey.

The survey will operate three 1.3 m telescopes at the Observatorio Astronomico Nacional (OAN) at San Pedro Mártir (SPM) in Baja California, México. Each telescope will be equipped with a custom high-speed camera capable of collecting image data on more than 10,000 stars at a readout cadence of 20 Hz. The resulting data volume will be enormous, with over 300 terabytes per year of raw image data.

All major construction at the site was completed in 2016, and the telescopes were installed in 2017. The cameras have been delayed due to supply chain interruptions stemming from the COVID-19 epidemic, but they are now on track for completion by the end of 2021. Survey operations are expected to begin in early 2022.