Gemini staff contributions
Science Highlights
Recent near-infrared observations at the Gemini North telescope are used to characterize KH 15D — a binary T Tauri system and its circumbinary ring . Spectrographic data from Gemini North provides the strongest evidence yet that massive stars form in much the same way as do lower-mass stars . A team of astronomers use GeMS / GSAOI data at Gemini South to create the most accurate , and deepest , near-infrared color-magnitude diagram of globular cluster NGC 6624 . And a joint program between Gemini North and the W . M . Keck Observatory on Maunakea completes the longest frequent , high-resolution imaging of Io ’ s thermal emission , revealing patterns in the Jovian moon ’ s volcanic activity over time and location .
Figure 1 . The top panel shows the spectrum of KH 15D during its “ bright ” phase , when the amount of direct starlight was greatest . The middle spectrum (“ intermediate ” phase ) was taken when star B was just below the edge of the ring . Both spectra in the bottom panel were obtained during “ faint ” phases from two different cycles , when both stars were near periastron and the contribution from starlight was minimized . The spectrum from November has been offset by 1.5x10 -15 W m -2 μm -1 for comparison to the data from December .
Unscrambling a Complex Young Stellar System
Nicole Arulanantham of Wesleyan University ( Middletown , Connecticut ) and colleagues used the Gemini Near-InfraRed Spectrograph ( GNIRS ) on the Gemini North telescope to target the binary T Tauri system V582 Mon ( KH 15D ) — two K-type stars in a circumbinary ring that is inclined to the binary ’ s orbit .
The team obtained data at three different orientations of the system ’ s two young stars ( Figure 1 ), allowing them to study several key aspects of this complicated system — including characterizing the photosphere and magnetosphere of the companion star ( B ), exploring a jet of material associated with a bipolar outflow , and probing the scattering properties of its circumbinary ring . The research uncovered an excess of near-infrared radiation that is possibly the signature of a self-luminous 10-Jupiter-mass planet . While this unresolved planet displays the expected excess in infrared radiation , as well as a 2-micron
January 2017 GeminiFocus
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