_______________________________________________________________________ NOTES FROM THE CTIOPI MEETING IN CHARLOTTESVILLE ON MAY 08-09, 2001 (http://www.chara.gsu.edu/RECONS/ctiopi.meeting01) _______________________________________________________________________ IN ATTENDANCE Jennifer Bartlett Todd Henry Phil Ianna Wei Chun Jao Rene Mendez Ricky Patterson John Subasavage _______________________________________________________________________ PROGRAM ISSUES 1. We have now reached month 22 of CTIOPI, and have 14 months remaining. The last observing run for CTIOPI at the 0.9m will almost certainly be July 2002. In August 2002, the camera that is currently on the 0.9m is to be moved to the newly-acquired 1.3m (formerly 2MASS), so the continuity of astrometric frame series will be lost. Although the 1.5m program is scheduled to end at the same time, it appears possible to extend it if needed. 2. In order to reduce the burden on CTIO staff, we have agreed to observe on the 1.5m telescope 4 nights every other month rather than 2 nights each month. This will help reduce the number of cage changes required. 3. NOAO rules indicate that we must save all frames and we will continue to do so. NOAO has not provided a specific plan as to how to make the data available to the community, although that will certainly remain an issue. What we CAN do now is provide preliminary parallaxes for target stars on the RECONS website. However, Ianna and Mendez pointed out that we must be sure not to make any parallax available that (1) can be used prior to publication or (2) violates agreements made with teams that provided targets prior to publication. 4. It was noted that the U. Virginia has a backup Apple 2E, in case the TCS explodes at the 0.9m. 5. We have 3 nights of spectroscopy on the CTIO 4.0m in July, which Henry and Lucianne Walkowicz will use to observe CTIOPI targets. It was noted that the ESO 3.6m and 1.5m telescopes are also available through Mendez. _______________________________________________________________________ GOALS The goals stated in the original CTIOPI proposal were: 100 stars/parallaxes within 20 parsecs accurate to 2 mas 100 stars/parallaxes within 20 parsecs accurate to 10 mas Our revised goal is now: 200 stars/parallaxes within 25 parsecs accurate to 3 mas The breakdown of current targets on the two telescopes is: 0.9m: 150 of 156 GOLD setups done + 8 calibration stars 1.5m: 66 of 81 GOLD setups done + 7 calibration stars _______________________________________________________________________ RESPONSIBILITIES To do lists were created at the meeting, and specific tasks are given here. Please let Henry know when these tasks have been accomplished! ---------- Henry ---------- mark a target's name on the web observing list if there is a note that should be read before making observations X develop method to indicate on observing list that stars are finished (e.g. LHS 3836) post results on RECONS website as "new stars in NStars" and list NAME, RA/DEC, V, ERROR (but not parallax!) X create a refraction/photometry observing list for all targets and post on the web (NAME, RA/DEC, VRI needed) select 3 stars that will have parallaxes determined at VRI at 0.9m to check for consistency X send words from CTIOPI proposal to Mendez/Costa for ESO proposal X start search for new multiple systems in CTIO data ---------- Ianna ---------- contact Alistair Walker and Stephanie Wachter about 1.5m camera scheduling to remind them that it is critical for us to have the same camera for all runs X get the 0.9m catalog completely up to date through April 2001 email Ruiz about Anguita archive of data X revise parallax program to incorporate additional precision in centroid positions and parallax factors get Barbara McArthur to run Gaussfit on a list of our centroids compare UVa/GSU vs HST pipeline results ---------- Jao ---------- add email to finish script for catalog generation: yale@mso.anu.edu.au write up cookbook for pipeline to point of centroids get better coordinates from GSC check for parallax plate calibration paper in AJ by Norbert Zacharias, who did the 0.9m a few years ago ask Nick Suntzeff at CTIO if he has a bad pixel map, otherwise take 100 zero frames, and median filter with cosmic ray rejection ---------- Mendez ---------- apply for ESO time to get VRI for 1.5m targets check into applying for ESO time to get spectra for Jao's thesis X get cookbook for HST parallax reduction pipeline get cookbook for Yale parallax reduction pipeline compare UVa/GSU vs Yale pipeline results develop program for conversion of relative to absolute parallax ---------- Patterson ---------- check on 2 nearby white dwarf candidates from Majewski ---------- Subasavage ---------- write up cookbook for U. Virginia parallax reduction pipeline finish reducing available VRI photometry from CTIOPI send .pif files to Jao and Mendez for APM0018, GJ1251, LHS3836 _______________________________________________________________________ OBSERVING 1. It was agreed that we need to do a better job of focusing! 2. More systematic monitoring of multiple systems is required. For any multiple that is resolved in CTIOPI frames, at least one frame each at VRI should be taken at each epoch. These systems are described in the "Notes on Objects Observed" web link. 3. We need to make MANY photometric observations at VRI for the conversion of relative to absolute parallax. We also need to make MANY refraction observations so that differential refraction can be addressed. We decided to COMBINE these two types observations into one method. Usually, you should devote an entire night to refraction/photometry frames, and take them as follows: Each parallax field should be observed 3 times at VRI (9 total frames) --- at 2H EAST, on the meridian, and at 2H WEST. Try to get within 15 minutes of these east/west limits. The positioning and focus are crucial! To calibrate the photometry, at least 3 photometric standards should be done at up to five locations. It is important to be sure that at least one of the standards is red. 4. The debate concerning efforts to correct for differential refraction was long and painful. Although we believe that the adjustments to final parallax due to refraction will be minor because we are observing very close to the meridian, there might be some significant adjustments required at the 1.5m because (1) the faint objects often require observing far from the meridian, and (2) there are very red targets. 5. Although we will try to make photometric/refraction observations for all targets, we will likely need additional photometry time on other telescopes. Costa and Mendez will apply for Chilean time to make photometric observations, in particular for the 1.5m targets. _______________________________________________________________________ DATA HANDLING AND STORAGE 1. Two copies of the data are being written to DAT tape. One copy goes to Ianna in the US, which is then passed along to Henry. The other copy goes to Mendez in Chile. 2. No definitive division of labor for the reduction to final parallaxes was decided upon, although in general, the 0.9m parallaxes will be reduced in the US and the 1.5m parallaxes reduced in Chile. Jao's pipeline will be duplicated for the Chile folks, once it is up and running. 3. Jao is building a pipeline through the centroid extraction phase which should speed up data processing. He outlined the pipeline, which has been modernized to use IRAF and SEXTRACTOR, rather than Figaro. Many IRAF steps have also been streamlined for more efficient basic frame processing (flat fields, bias subtraction, etc.). The end product of this software will be centroid positions. The centroids for targets and their reference stars generated at GSU will be used with U. Virginia software to generate parallaxes and proper motions. 4. Ianna volunteered to do a comparison between the UVa/GSU and HST parallax reduction software. Mendez volunteered to do a comparison between the UVa/GSU and Yale parallax reduction software. These will be a crucial tests of our methodolgy. _______________________________________________________________________ PUBLICATIONS Specific near-term papers are: 1. Photometry of SSO/CTIO Nearby Star Candidates (Ianna/Subasavage lead) 2. New Multiples Found During CTIOPI (Henry/student lead) Henry proposed several natural subsamples that would provide a vehicle for each CTIOPI member to lead efforts to publish different astrometric results. These are not definitive, but are useful in thinking about how to break this large effort into manageable "individually publishable units". The following numbers reflect the breakdown in targets as of the writing of these notes (26 JUN 01), and possible first authors are listed: ------------------------------------------------------------ Author Program 0.9m 1.5m combined TOTAL ------------------------------------------------------------ Costa WTC 7 11 18 CALESO 4 6 10 28 Henry RECONS 28 6 34 34 Ianna APM 2 9 11 MASSIF 26 1 27 38 Jao (thesis) MOTION 34 19 53 53 Mendez DEN 3 13 16 2MA 0 4 4 SPM 0 2 2 22 NSTARS* 52 10 62 62 PLXCAL 8 7 15 15 white dwarfs? ------------------------------------------------------------ TOTAL 164 88 252 ------------------------------------------------------------ * The NStars sample consists of stars not fitting nicely into the other samples. In general, these are stars that are beyond 12 pc (the RECONS sample cutoff) but possibly within 25 pc. It was agreed that what was decided at the first CTIOPI meeting in August 1999 will still be the authorship policy: "Authors on all CTIOPI papers will include the six coinvestigators plus any students/postdocs who do SIGNIFICANT work on the project. Lead authors will be determined by who is leading a particular effort (astrometry, photometry, spectroscopy), combined with those who have taken responsibility for developing astrophysically interesting sub-samples." However, the six coinvestigators are now five, and THE FOLLOWING INDIVIDUALS SHOULD BE ON ALL PAPERS REPORTING ASTROMETRIC RESULTS: ******************************************** ***** Costa, Henry, Ianna, Jao, Mendez ***** ******************************************** Additional individuals who have been a part of CTIOPI at some time were discussed individually: Anguita yes, WT stars Begam no Miranda maybe, possibly some papers Patterson yes, photometry paper Pujals yes, photometry paper Ruiz yes, CALESO stars Saunders no Seitzer maybe, offer as last author on early paper Subasavage yes, possibly several papers For papers that report PHOTOMETRIC results achieved using CTIOPI time, not all five of the core members must be on the paper. However, all those who have done significant work should be on the paper. In general, the US folks will reduce photometry from the 0.9m and the Chilean folks will reduce photometry from the 1.5m. External authors, i.e. those who provided targets before publication, would not necessarily be invited to be on the papers. The first stage in discussing this with a potential author would be to ask if an acknowledgment is sufficient. However, promises may have been made at the time when unpublished targets were provided (Delfosse? Gizis? Scholz?) even though the targets may be published now. In some of these cases an author may be added. Clearly, if the target is still not published at the time of a parallax result, then the individual who provided the target must be added to the paper. _______________________________________________________________________ THE FUTURE The future of work at CTIO can be broken down by telescope, as the CTIO staff begins to focus on the larger Gemini South, SOAR, and SST projects. 0.9m it could be run by a consortium, although the current camera is to be moved to the 1.3m after July 2002 1.3m will get the camera currently on the 0.9m, this is a modern telescope that we should consider for "CTIOPI-2" 1.5m possibly will become a 60% YALO telescope, but it is likely that we can still get some time to finish 1.5m targets after July 2002 4.0m the new infrared camera built by Ron Probst has 0.3"/pixel scale and an 11' field that makes it ideal for astrometry, it is scheduled to be on the telescope in January 2002, plans are to keep it mounted and stable on the side port Mendez pointed out that providing a guider or other piece of hardware for the 1.3m might allow us to acquire a chunk of observing time. Another option might be to hire Miranda to build components for the 1.3m, given that he has some background in telescope mechanics. What Henry proposed is to begin thinking of finishing CTIOPI-1 on the 0.9m and 1.5m, and consider developing a CTIOPI-2 concept that would use the 1.3m and 4.0m. Ron Probst is also interested. Henry, Ianna, and Mendez all liked this idea... Here we go again! _______________________________________________________________________