Fall 2010 News
Last updated 1 September 2010
Proposal Deadline for Semester 2011A (February 1, 2011 - July 31, 2011) is Friday, October 1, 2010.
Available instruments are listed here. Remote observing is offered from any location with broadband Internet access for any project that utilizes IRTF instruments. Click here for more information.
Telescope Allocation Committee
The current TAC members are Gordon Bjoraker (Goddard), Michael Gregg (Lawrence Livermore Nat. Lab.), Kevin Luhman (Penn. State), Susan Lederer (Johnson Space Center), Mark Buie (SWRI), and Tracy Beck (STScI). This committee consists of three solar system and three non-solar system members. The members who rotated off are Eilat Glikman (Yale), Luke Keller (Ithaca College) and Michael Kelley (U. of Maryland).
Science Highlights and Publications
Our Science Highlights page is updated regularly as we receive the latest highlights from you. These highlights are sent to our funding agencies, NASA and NSF, to keep them abreast of the exciting and useful science obtained at the IRTF. See examples here. Please continue to submit your new publications using the form provided on our website, or send your reprints to William Walters. Please acknowledge the IRTF in your publications following the instructions shown here. It is important that you include in your papers the name of the instrument used and the citation for the instrument, as this helps to insure future funding of IRTF instruments. For AAS publications, please include the facility keyword and instrument, such as IRTF:SpeX. Look here for more information.
Non-standard Observing Programs
We have a program to observe Titan whenever it is up and SpeX is on the telescope "Titan's Methane Meteorology: Context for Cassini Titan Flybys T63-T66" (PI: E. Schaller). This program is aimed at discovering new cloud features on Titan (see the Press Release). If there is evidence for activity then adaptive optics imaging is obtained at the Gemini or Keck observatories. The observing time is noted on the schedule and there is flexibility on when the observations are taken.
IRTF Spectral Library
Users are encouraged to make use of the spectral library, which is available here. The paper on Cool Stars has been submitted to ApJS and will be posted on the website when accepted for publication. Contact John Rayner for more details.
NEO Spectral Survey
The MIT-IRTF Near-Earth Object spectral survey is underway, and many spectra are publicly available. See the side bar for more information or go to smass.mit.edu/minus.html.
The IRTF is making headlines for its work on the outer planets and Mars. See the articles below.
||How do you use a telescope that is over 30 years old to conduct cutting edge astronomy? That was the question posed to one of our newest employees, Dr. Michael Connelley. As one of the IRTF's support astronomers, Connelley believes he has the answer. "Collecting valuable data comes from the proper alignment of the telescope," Connelley said. |
|With the help of the former IRTF Deputy Director Eric Tollestrup, Connelley has been tasked with commissioning two new secondary mirrors for the IRTF Telescope. Connelley is using this opporunity to study everything that goes into how the mirrors are mounted, aligned and how they interact with the rest of the telescope. Although he was recently hired by the IRTF in February of 2010, Connelley is no stranger to the facility having been a graduate student with IRTF from 2003 to 2007. Connelley grew up in Hawaii graduating from Iolani High School in 1996 and receiving his Ph.D. in astronomy from the University of Hawaii. Normally accustomed to working with other astronomers, Connelley said one of his biggest challenges is working with a diverse set of engineers, technicians and managers many of which have more experience at the IRTF and use different skills. Before coming to work with IRTF Connelley was a postdoctoral researcher at the NASA Ames Research Center working with Tom Greene on a spectroscopic survey with embedded protostars. On his own time Connelley enjoys amateur astronomy and has built several of his own telescopes. He also has a strong interest in photography and classic cars.|
Two significant milestones have been achieved in the program to upgrade SpeX. The H2RG infrared detectors have been received, and the new array controller has its first IRTF specific pre-amplifier electronics board. The new array controller draws from the Stargrasp controller originally designed for Pan-STARRS, but it will have special modified features that make it specific to the IRTF. This IRTF version of the Stargrasp controller will eventually be common to three instruments including the SpeX upgrade, iSHELL and NSFCAM2. The controller and its newly minted pre-amplifier board are presently undergoing bench testing at the Hilo IRTF laboratory. Cryogenic tests of the new low-noise cabling scheme for the H2RG have been successfully completed using the lab test dewar, together with plans to modify the SpeX cryostat to mount the Stargrasp controller. The IRTF Stargrasp controller will initially be deployed and tested in NSFCAM2. Once these tests are successful the IRTF Stargrasp will be used in the SpeX upgrade and in the iSHELL instrument once they have completed fabrication. Contact John Rayner for more details.
Lars Bergknut is currently on a "Mission of MIRSI." That is, the MIRSI instrument has been removed from the telescope, and Bergknut has taken on the challenge of bench testing its performance prior to breaking it down for a total systems diagnostics and evaluation. The goal is to bring the instrument, which has been on loan to IRTF from Boston University, back to its original liquid helium consumption rate. When it was first received in 2005 from its manufacturer Infrared Labs in Arizona, it had a boil off rate of 16 liters a day. Over the years it has increased to 25 liters a day making the instrument costly to use and maintain. Bergknut and instrument technician Darryl Watanabe are excited to evaluate MIRSI's internal components to see if anything can be repaired or optimized. If MIRSI can be returned to its original opreating parameters or even improved upon, it will make it less expensive for observers to use. MIRSI is expected to be fully refurbished and back in service by October 30, 2010.
|Lars Bergknut delves into the inner workings of the MIRSI Instrument.|
This camera has been used on a conditional basis because of the high read-noise, which decreases the sensitivity at JHK. It has been determined that the current array should be replaced with a new H2RG array from Teledyne Scientific & Imaging. Because of obsolete components in NSFCAM2, a new set of control electronics is currently being developed called the IRTF Stargrasp controller (as mentioned above). The NSFCAM2 camera will be the first instrument to receive the IRTF Stargrasp controller, and it will act as a test bed for the new controller before it's deployed in the SpeX upgrade and the iSHELL instrument both currently under fabrication. Be advised that the NSFCAM2 is currently best suited for observations in the thermal infrared (3-5 microns), since it is background limited and the image quality is excellent, or where a wide field of view of 0.04 arcsec pixels is required. Please check the status of this instrument before writing a proposal by contacting Bobby Bus.
CSHELL is working normally. The new user GUI is now in regular use. Please be advised that observing macros written for the old GUI should be tested prior to observing. This semester CSHELL is going to be used to demonstrate a calibrating technique that uses custom-made gas cells during an observation run in November 2010. If this proves successful, the resulting data could discover planets outside of our solar system, additionally this approach may also be used to calibrate the new iSHELL instrument, which is currently under development. Contact John Rayner for more details.
Now that the science and engineering grade H2RG infrared detectors have been received from Teledyne Scientific & Imaging, the engineering of the instrument itself is switching into high gear. The preliminary optical design and scattered light analysis is complete. Optical and mechanical tolerance analysis is continuing. Lead mechanical engineer Tim Bond has already mapped out the different folds the light path will take. Dimensioning and placement of all the instrument's various internal components is now currently underway. Bond has been assigned the critical task of translating the lofty science requirements, developed by Dr. John Rayner, into tangible engineering specifications. Another advancement in the iSHELL project is the base material for the Silicon Immersion Grating has been produced by the vendor Toppan Photomask Inc. This material is currently at the University of Texas (UT) where a special grating will be applied using micro-machining techniques that UT has perfected over the last decade. When completed the spectral resolving power of this instrument will be approximately 70,000 making it an exciting new tool in the Northern hemisphere for scientific discovery. A PDF copy of the proposal can be downloaded here. We welcome input from the community on this new major instrument for the IRTF. Contact Alan Tokunaga if you have any questions or comments about the proposal.
New Secondary Mirrors:
With the help of former IRTF deputy director Eric Tollestrup, Michael Connelley is now the primary lead investigator charged with commissioning the IRTF's two new secondary mirrors. The first of the two mirrors, figured by Optical Surface Technologies in New Mexico, received a special silver coating coupled with a protective AL203 overcoat by L&L Optical Services in Santa Ana California. Connelley will be testing the new mirror's performance during an engineering run from September 7th through September 10th, 2010. The commissioning process also presents the opportunity to re-evaluate everything surrounding the performance of the mirrors including the methods we are using to fasten the mirror to the telescope, how we are aligning it to the primary mirror, and how it works with the chopping secondary mechanism. The goal is to improve the telescope's image quality since the new secondary is figured to remove the spherical aberration in the primary mirror.