Fall 2013 News
Last updated 6 September 2013
Proposal Deadline for Semester 2014A (February 1, 2014 - July 31, 2014) is Tuesday, October 1, 2013, 5PM Hawaii time.
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 Kevin Covey (Cornell University), Ted Kostiuk (Goddard Space Flight Center), Vishnu Reddy (Planetary Science Institute), Kris Sellgren (Ohio State University), Jason Surace (Caltech), and Leslie Young (SWRI). This committee consists of three solar system and three non-solar system members. The member who rotated off is Andy Rivkin (Johns Hopkins Applied Physics Lab).
Help Keep Our Publications List Current
Please continue to 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.
Non-standard Observing Programs
The C/2012 S1 (ISON) observing campaign will not be extended into semester 2014A. However we would like to continue archiving any additional comet ISON data on a voluntary basis. Information on comet ISON can be found at:
The IRTF comet ISON data archive is online:
IRTF Comet ISON Data Archive
IRTF Spectral Library
Users are encouraged to make use of the spectral library, which is available here. Citations for the papers that have been published can be found here. 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.
NSFCAM2 is working normally and is available for use in 2014A. Sky flats and dome flats at J, H, and K bands were recently taken with NSFCAM2 and compared. The goal was to see if dome flats would work instead of sky flats, since the sky at night (especially at J) is quite dark, thus requiring a long time to obtain good flats. The sky flats were taken on sky near sunset, and the dome flats were taken by pointing the telescope at the white spot on the dome with the dome lights on. When considering the data we can see gradients in the ratio between the sky and dome flats. The amplitude of the non-uniformity is about +/- 5% (peak-to-valley is about 10%). The conclusion is that dome flats are not useful except for crude data reduction when photometry is not important. Otherwise, sky flats are necessary. If you are taking data at JHK, plan to take twilight flats at either sunrise or sunset. If your run is scheduled in the middle of the night, then arrangements can be made to take flats for you either before or after your run. For more information contact Michael Connelley.
SpeX will not be available in semester 2014A. It will be removed from the telescope and returned to Hilo on February 3 2014 for upgrade. Since the MORIS CCD imager is mounted on SpeX it will also be unavailable until SpeX is back. The upgrade involves replacing the now obsolete spectrograph and slit viewer array controllers (few spare boards remain) with new array controllers from ARC, Inc. The new controllers have been built and are currently being tested. The Aladdin 1024x1024 InSb array in the spectrograph will be replaced with a science grade 2048x2048 Hawaii 2RG array, which is already in-hand. The engineering grade 512x512 Aladdin InSb array in the slit viewer will be replaced by the science grade InSb array currently in the spectrograph. We expect improved sensitivity and increased simultaneous wavelength range in the spectrograph and improved sensitivity in the slit viewer/IR guider (same 60"x60" FOV). Resolving power will remain unchanged but with improved pixel sampling. A new version of Spextool will be available for the changed array format. For more information contact John Rayner.
Due to the SpeX upgrade, MORIS will not be available in the 2014A semester. The MORIS instrument is a 512x512 pixel Andor CCD camera mounted at the side-facing, dichroic-fed window of the SpeX cryostat (60"x60" field-of-view). MORIS stands for MIT Optical Rapid Imaging System, and it was built by the Massachusetts Institute of Technology following on the successes of the POETS occultation systems. MORIS can be used simultaneously with SpeX and can even guide SpeX in place of Guidedog. For more information on this technique contact Bobby Bus.
CSHELL is a 1-5.5 micron high-resolution echelle spectrometer. It uses a 256 x 256 InSb array. CSHELL is working normally. The built-in CCD guider is less reliable when used under high background conditions (daytime guiding). Contact John Rayner for more details.
Work on the Immersion Grating Echelle Spectrograph (iSHELL) continues. Design work on the mechanisms is almost finished, and machine shop drawings are being produced for the mechanisms. All of the optical components for the spectrograph and slit viewer have been ordered. The priority now is to finish the cryostat and calibration box design. We will have delivery of our science grade detector this month. A second science grade immersion grating has been fabricated by the University of Texas Austin group headed by Dan Jaffe. Our plan is to begin assembly of the mechanisms in the spring of 2014 and followed by the assembly of the cryostat during the summer.
Due to a failure of the array electronics, MIRSI continues to be unavailable in the 2014A semester. We are considering upgrading the MIRSI electronics, but this work has still not been scheduled. Please watch this site for future updates on the status of MIRSI, or contact the IRTF staff for more information.
Dome and Shutter Upgrades Completed:
Upgrades to the IRTF’s dome and shutter mechanisms are complete. The dome drive system was refitted with three brushless servomotors from Baldor. The dome’s entire bottom rail was also machined to a smooth finish. This process required special programming to the telescope’s control system in order to move the dome at a very slow and controlled speed for the cutting tool. A slight angled profile was also restored to the bottom of the dome rail. This profile became worn away over the years but once restored proved vital to the way the dome centered itself with its guide wheels. The end result is that the now dome moves smoothly. Additional work to replace worn out dome supporting wheels and guide rollers are in progress.
The shutter mechanism was also upgraded to use power cables sheathed in a flexible plastic energy chain that is tucked neatly away in a curved trough that matches the arch of the dome. The present shutter power bus bar is prone to several types of failure modes. This upgrade, when completed, should eliminate these problems and make the shutter operate more reliably.