Press Release

When a person looks up into the nighttime sky, they see stars, planets, and galaxies across a sea of darkness. The movements of planets and seasonal variations to the constellations have been relatively the same for thousands of years. What if the sky changed overnight and a new star brighter than anything else appeared? Would it be noticed if it happened in the 16th century?

Suprime-Cam is the 80 million pixel digital camera positioned at Subaru’s prime focus collecting high quality pictures over a 30 arc minute area of sky. For over ten years, Suprime-Cam has been an effective research tool providing images with high levels of detail and contrast, and has been used in the study of galaxies and to peer towards the distant edges of our Universe. In order for Subaru to remain a front-runner in astronomical study, Suprime-Cam was recently upgraded and enhanced. In a collaboration between NAOJ and Hamamatsu Photonics, new highly sensitive CCDs were developed and installed in Suprime-Cam. This instrument upgrade doubled sensitivity thereby significantly improving imagery and also greatly reducing observing time. The CCD transformation is the first step in the design of the next generation camera at Subaru, Hyper Suprime-Cam.

As scientists study the interconnectedness of environmental systems on Earth, astronomers are looking at environmental forces in the Universe to see how they affect the evolution of galaxies. These forces can change the shape, color, and size of galaxies, and do so in ways that are hard to pinpoint -- until now.

Galaxies evolve over time by changing shape, size, and color. Understanding the evolutionary processes of galaxies is one of the most important issues in astronomy for which there are still fundamental problems to be solved. One straightforward approach is to study clusters of galaxies that contain several thousands to tens of thousands of galaxies. Galaxy Clusters are dense populations of galaxies, rich with hot intergalactic gas, accompanied by strong gravitational forces. These clusters are the best location to observe environmental effects in galactic evolution.

A large team of international astronomers, using a suite of telescopes, has uncovered a distant galaxy producing stars much faster than ever seen before. The study used the Subaru Telescope and other earth-based observatories along with the Hubble and Spitzer Space Telescopes to witness a starburst galaxy 12.3 billion years light away. Using varying wavelengths ranging from visible to radio, astronomers estimated the star-formation rate of the galaxy to be about 1,000 to 4,000 stars per year. The findings suggest that this accelerated activity may be the formation of one the most massive elliptical galaxies in the Universe.

We have all dreamed of using a time machine to go back in history. What’s exciting is that astronomers at Subaru went back in time to observe light that originally arrived at Earth more than 300 years ago. They didn’t use a time machine, but something similarly interesting called a “light echo”.

An international team of scientists has discovered a wave or oscillation in Saturn’s atmosphere. For over 20 years, NASA scientists have been studying temperature changes in the upper atmosphere of Saturn using data from several telescopes on Mauna Kea and, more recently, up-close information from the Cassini spacecraft. The findings show temperature fluctuations rippling back and forth like a wave above and below Saturn’s equator. The Subaru Telescope played an important role in the project, and two Subaru astronomers contributed to the team’s success. The study shows a common link to similar phenomena on Earth and Jupiter, and further research hopes to determine why Saturn’s atmospheric temperature changes with the seasons.

A team of international astronomers from Ehime University, Tohoku University, and the California Institute of Technology studied a group of newborn galaxies 12.5 billion light years away. The scientists discovered 80 small galaxies using the Subaru Telscope, and conducted follow-up observations with the Advanced Camera for Surveys on the Hubble Space Telescope. As result, they have discovered that 17 out of 80 galaxies have only the size of 4000 light years. This was the first time the HST had completed a systematic study of the detailed shapes of newborn galaxies. The results identified galaxies 10 to 30 times smaller than current known galaxies. This will reaffirm the theory that small newborn galaxies have combined repeatedly to become larger galaxies over the past 10 billion years. The observations show scenes of galactic formation anticipated through theoretical studies.

(Japanese only)

(Japanese only)

A collaborative team of researchers from the University of Tokyo, Hokkaido University, and Hiroshima University carried out multi-wavelength observations of supernova (SN) 2006jc using the Subaru Telescope's Faint Object Camera And Spectrograph (FOCAS), the MAGNUM Telescope and KANATA Telescope, as well as the infrared astronomical satellite AKARI. The optical observations with the Subaru Telescope were conducted over a 6-month period and revealed sudden fading of SN 2006jc only 2 months after the explosion. Together with the AKARI infrared observations, the team pinpointed the site of dust formation in the supernova ejecta. Furthermore, a comparison between theoretical calculations and physical observations illustrated a scenario under which a massive star with more than 40 solar masses undergoes extensive mass loss during its life that ultimately ends with a supernova explosion.

(Japanese only)

(Japanese only)

International astronomers on the COSMOS project announced a large catalogue of strong gravitational lenses in the distant Universe. Based on the observations with Hubble Space Telescope and several ground-based telescopes including the Subaru Telescope, a staggering 67 new gravitational lensed galaxies were identified around massive elliptical and lenticular galaxies. This sample demonstrates the rich diversity of strong gravitational lenses, and, if this sample rate has statistical significance, there would be nearly half a million similar gravitational lenses in total over the whole sky. Once more lenses are found, a census of galaxy masses in the Universe can be created.

A team of Japanese astronomers resolved a circumstellar disk around the young lightweight star FN Tau. The diminutive star is located in a star-forming region toward the Constellation Taurus at a distance 460 light years from Earth. This research group used the Coronagraphic Imager with Adaptive Optics (CIAO) at the Subaru Telescope to directly image FN Tau and the lightweight disk of planet-forming material surrounding it. This star is merely 100 thousand years old and weighs only one tenth of the Sun.

A research team of astronomers from Tokyo University, Hiroshima University and so on, observed 15 supernovae at 200 or more days after the explosion, using FOCAS at Subaru Telescope. Contrary to the traditional view as spherically symmetric expansion, they revealed that supernovae are commonly asymmetric. The final stage of a massive star's life and the supernova explosion mechanism are still big mysteries. This study boosts the research of not only the supernovae but also another mysterious object - Gamma Ray Bursts.