GeminiFocus January 2018 - Page 4

In their Nature paper ( published online ; November 20 , 2017 ), Karen Meech and her collaborators argue that while ‘ Oumuamua ’ s colors ( and therefore , possibly , composition ) are similar to those of outer Solar System bodies , its shape isn ’ t : the large variation in brightness , by an order of magnitude over the object ’ s 7.3-hour rotation period , points to an extremely ( for Solar System standards ) elongated object ten times longer than it is wide .
Two other teams also used Gemini data to study ‘ Oumuamua , and Gemini ’ s new Chief Scientist , John Blakeslee , summarizes these results in this issue ’ s lead science article starting on page 4 . Will we get another chance to study interstellar asteroids like ‘ Oumuamua ? Certainly yes ; a recent study ( Trilling et al ., arXiv : 1711.01344 ) suggests that we ’ ll have at least one opportunity per year once the Large Synoptic Survey Telescope ( LSST ) starts operations adjacent to Gemini South on Cerro Pachón .
Technical Thrills
Moving on to technical activities , on October 26th , just as ‘ Oumuamua was making its way through the Solar System , staff at Gemini South propagated the Gemini Multi-conjugate adaptive optics System ( GeMS ) laser guide star constellation for the first time with the new Toptica laser . This was the first of several important steps designed to restore GeMS to its intended performance . The new Natural Guide Star Wavefront Sensor ( NGS WFS 2 ), expected to be commissioned later next year , will be an order of magnitude more sensitive than the current one , providing up to a 30 % increase in the fraction of the sky accessible to GeMS .
A new ground Deformable Mirror , DM0 , to replace the one that failed shortly after commissioning , will also be received later next year . After that , efforts will concentrate on GeMS ’ Real Time Computer ( RTC ), not only to improve its reliability but also to support the new generation of visiting instruments , almost all of which are designed to exploit GeMS ’ unique capabilities .
In the North , we have commissioned a new visiting instrument : ‘ Alopeke ( BTW : a huge THANK YOU to the ‘ Alopeke team for their cooperation during the ‘ Oumuamua observations which interrupted their work ). Many Gemini users are familiar with our visiting Differential Speckle Survey Instrument ( DSSI ). Well , ‘ Alopeke is DSSI on steroids : it is capable of diffraction-limited optical imaging ( Full-Width at Half-Maximum 0.016 arcsecond at 500 nanometers ) of targets as faint as V ~ 17 magnitude over a 6.7 arcsecond diameter field-of-view ( as opposed to DSSI ’ s 2.8 x 2.8 arcsecond field ). It also includes Sloan Digital Sky Survey as well as narrow band filters , and offers a wide-field mode ( 1 arcminute diameter ) that , while not reaching full speckle performance , can still clock an impressive 26 frames per second .
‘ Alopeke is now permanently mounted at Gemini North , and I urge the Gemini community to take a closer look at its capabilities . While it was motivated by the desire to understand how many stars that host planets are in binary systems , ‘ Alopeke also holds tremendous potential for the study of crowded stellar fields … the centers of Galactic globular clusters or Local Group galaxies come to mind .
More Exciting News and Initiatives !
On the governance side , the last three months have marked two milestones for the National Center for Optical and Infrared Astronomy ( NCOA ): the operations and management plan developed for NCOA was validated first by an external panel
2 GeminiFocus January 2018
In their Nature paper (published online; November 20, 2017), Karen Meech and her collaborators argue that while ‘Ou- muamua’s colors (and therefore, possibly, composition) are similar to those of outer Solar System bodies, its shape isn’t: the large variation in brightness, by an order of magnitude over the object’s 7.3-hour rota- tion period, points to an extremely (for So- lar System standards) elongated object ten times longer than it is wide. Two other teams also used Gemini data to study ‘Oumuamua, and Gemini’s new Chief Scientist, John Blakeslee, summarizes these results in this issue’s lead science ar- ticle starting on page 4. Will we get another chance to study interstellar asteroids like ‘Oumuamua? Certainly yes; a recent study (Trilling et al., arXiv:1711.01344 ) suggests that we’ll have at least one opportunity per year once the Large Synoptic Survey Tele- scope (LSST) starts operations adjacent to Gemini South on Cerro Pachón. Technical Thrills Moving on to technical activities, on Oc- tober 26th, just as ‘Oumuamua was mak- ing its way through the Solar System, staff at Gemini South propagated the Gemini Multi-conjugate adaptive optics System (GeMS) laser guide star constellation for the first time with the new Toptica laser. This was the first of several important steps designed to restore GeMS to its intended performance. The new Natural Guide Star Wavefront Sensor (NGS WFS 2), expected to be commissioned later next year, will be an order of magnitude more sensitive than the current one, providing up to a 30% in- crease in the fraction of the sky accessible to GeMS. A new ground Deformable Mirror, DM0, to replace the one that failed shortly after commissioning, will also be received later 2 GeminiFocus next year. After that, efforts will concen- trate on GeMS’ Real Time Compute "%D2BǒF&fRG2&VƖ&ƗG'WB6F7W'BFRWrvVW&Fbf6FrЧ7G'VVG27Bbv6&RFW6vV@FWBvT>( VVR6&ƗFW2खFR'FvRfR6֗76VBWpf6Fr7G'VVC( VR%EsVvPDRFFR( VRFVf"FV 6W&FGW&rFR( VVV"Ч6W'fF2v6FW''WFVBFV"v&vV֖W6W'2&Rf֖Ɩ"vFW"f2ЦFrFffW&VF7V6R7W'fW7G'VV@E54vV( VR2E547FW&G3@26&RbFfg&7FƖ֗FVBF6ЦvrgVvGFBbV`&76V6BBSWFW'2bF&vWG02fB2grvGVFRfW"br&2Ч6V6BFWFW"fVBbfWr26V@FE54( 2""&76V6BfVBB66VFW26FvF67W'fW2vV0'&r&BfFW'2BffW'2vFRfV@FR&6֖WFRFWFW"FBvR@&V6rgV7V6RW&f&6R67F66&W76fR#bg&W2W"6V6B( VR2rW&VFǒVFVB@vV֖'FBW&vRFRvV֖6ЦVGFFR66W"BG26&ƒЧFW2vRBv2FfFVB'FRFW6&PFVFW'7FBr7F'2FB7@WG2&R&'77FV2( VR6G2G&VVFW2FVFf"FR7GVG`7&vFVB7FV"fVG>( bFR6VFW'2bvЦ7F2v'V"6W7FW'2"6w&WvЦW26RF֖B&RW6FrWw2@FFfW2FRvfW&6R6FRFR7BF&VPF2fR&VBGv֖W7FW2f FRF6VFW"f"F6Bg&Ч&VB7G&ג4FRW&F2@vVVBFWfVVBf"4v2fƖFFVBf'7B'WFW&VV'#