In Part 1 – ACE Ambassador Adventure – Optical Observatories – Cerro Pachon, I covered the ACEAP 2020 cohort’s travels in Santiago, La Serena, Vicuna and Cerro Pachon (Gemini South, SOAR and Vera Rubin Observatory).
After checking into the astronomer’s housing at CTIO, we next experienced sunset and stars atop Cerro Tololo. Playing around, ACE ambassadors twilit torsos spelled the initials of our group. With the Blanco Telescope dome looming over us, and the inversion layer below us, the southern sky was ours. Most of us took nightscapes. One ambassador got out her Evscope. CTIO’s CPC 1100 worked on visual and live stacking of deep-sky objects such as the Tarantula Nebula. I used my 8x42 monocular to view the Magellanic Clouds, 47 Tucanae, Southern Pleiades, etc. All the while, the 4-meter Blanco telescope was at work behind us.
The sky was excellent, my SQM-L readings were 21.5. We were above the marine layer inversion from the Pacific less than 100 miles west.
After another short night’s rest, we awoke to more extensively explore Cerro Tololo. First stop included desayuno con huevos at the marvelous observatory cafeteria. Our host, Juan Seguel, then expertly led us through the numerous telescopes dotting the summit and nearby ridges, including the dome swarm known as the Mushroom Farm.
We started with the Blanco 4-meter telescope. This classic large telescope is the twin of the Mayall Telescope at Kitt Peak and saw first light in 1976.
Named for the Puerto Rican astronomer instrumental in bringing large telescopes to Chile and almost 50 years old, it stays young and productive by replacing its instrumentation. Now it’s almost exclusively devoted to the current largest camera in the world, the Dark Energy Camera or DECAM. At prime focus, the camera replaces the secondary mirror of the scope. No one knows what dark energy is but it is behind the accelerating expansion of the cosmos. The surveys by DECAM over the past decade image galaxies and take out the effects of matter including dark matter and study what’s left to try to get a handle on dark energy. Along the way, a lot of the sky is recorded. A recent release covered 3 billion stars mapped in our Milky Way galaxy.
We got the SMARTS – Small and Medium Research Telescope System – by visiting several of its scopes at CTIO. The 1.5-meter reflector had first light in 1968 and its classic control planet with RA-DEC readouts, control paddle and red LEDs is still functional. It reminded me of scopes I used during my graduate work back in the day. (There was even a disused photographic darkroom in the 1.5-meter dome! Memories of stop bath, glass plates and safelights) This scope and its smaller kin – 1.3, 1.0 and 0.9 meters – all are heavily involved in exoplanet followup observations for TESS and Kepler mission discoveries.
The smallest aperture instrument on the mountain is merely 0.03 meters or 30mm. It’s the GONG Global Oscillation Network Group’s solar telescope. Housed in a shipping container and fed by an external heliostat, it’s looking at the sun as much as possible to monitor our star’s helioseismology, the waves that travel through the sun revealing much about the solar interior.
Another night under cielos claros y oscuros. I nabbed a shot of the stars wheeling around the south celestial pole to add to my collection of north celestial pole star arcs.
The next day was a big transition back to the aerial hub of the country in Santiago. We drove back along the Ruta de las Estrellas, spotting semi-wild horse-donkeys, vineyards and hillsides covered with cardon cacti. We passed through a tunnel whose dimensions were expressly designed by the Chilean government to pass 8-meter-diameter telescope mirrors.
The small town of El Molle on the Rio Elqui is clearly astro-influenced, with murals of solar eclipses and starscapes on walls. And the ACE ambassadors were easily lured into the dulceria and its empanadas delicioso!