Astronomers utilizing the Subaru Telescope and W.M. Keck Observatory on Mauna Kea have made significant discoveries in the field of astronomy. They identified a massive planet and a brown dwarf orbiting distant stars, findings that enhance our understanding of the formation and evolution of giant planets and substellar objects. These results are part of the new Observing Accelerators with SCExAO Imaging Survey program, known as OASIS.
Thayne Currie, a professor at the University of Texas at San Antonio and principal investigator of OASIS, highlighted the importance of these discoveries. “These discoveries may help advance our abilities to image another Earth with future space-based observatories such as NASA’s Roman Space Telescope,” Currie stated. He emphasized the unique observational conditions at Mauna Kea, which combined with cutting-edge instrumentation, facilitated these remarkable findings.
Notable Discoveries: HIP 71618 B and HIP 54515 B
The first discovery, designated HIP 71618 B, is a brown dwarf with a mass equivalent to 60 Jupiter masses, located approximately 169 light-years away in the constellation Bootes. Often referred to as “failed stars,” brown dwarfs form similarly to stars but do not achieve the necessary mass for nuclear fusion. Consequently, they are cooler and fainter in visible light compared to their brightness in infrared wavelengths, which can be captured by the Subaru Telescope and Keck Observatory.
Data from Keck/NIRC2 and Subaru/SCExAO, collected within days of each other, led to the identification of this companion. Subsequent measurements over the following year from both observatories helped clarify the companion’s orbital characteristics.
The second discovery, HIP 54515 B, is an 18-Jupiter-mass planet orbiting a star located 271 light-years away in the constellation Leo. This planet’s distance from its host star is akin to Neptune’s orbit around the sun, though it appears exceptionally close to its star from Earth—similar to the size of a football viewed from over 200 miles away. The Subaru Telescope’s SCExAO system produced the ultra-sharp images necessary to distinguish this faint giant planet next to its bright star.
Upcoming Events and Observational Opportunities
Astronomy enthusiasts can look forward to the Quadrantids meteor shower, which will peak on the night of January 3 into the early morning of January 4, 2024. This meteor shower, originating from the asteroid 2003 EH1, can produce up to 40 meteors per hour at its peak. With minimal moonlight interference expected this year, observers in Hawaii will enjoy favorable viewing conditions, especially after midnight when the radiant in Bootes rises higher in the sky.
In January, the star family Kekaomakali‘i, known as the “Bailer of Makali‘i,” will be prominent in the night sky. This starline, integral to traditional Hawaiian navigation, features notable stars such as Hokulei (Capella), Na Mahoe (Gemini), Kapuahi (Aldebaran), A‘a (Sirius), and Ke Ali‘i Kona i ka lewa (Canopus). The Pleiades cluster, also part of this celestial guide, continues to shine brightly, marking the ongoing makahiki season, a time for rest and renewal in Hawaiian culture.
For early risers, Jupiter (Ka‘awela) will remain visible in the pre-dawn western sky throughout January, acting as a brilliant beacon before sunrise. Observers can also look toward Hokupa‘a in the north to catch a glimpse of the Big Dipper just before dawn.
For more information about the OASIS program and its findings, visit the official websites of the Keck Observatory and the Subaru Telescope. The discoveries made at Mauna Kea not only advance scientific knowledge but also inspire awe in the wonders of the universe.
