<=== observer ===> "CLEINERT",\ "Leinert, Ch.",\ "",\ "Max-Planck-Institut f\"ur Astronomie",\ "K\"onigstuhl 17",\ "",\ "D-69117",\ "Heidelberg",\ "Germany",\ "49 6221 528264",\ "49 6221 528246",\ "leinert@mpia-hd.mpg.de" <=== proposal ===> "PROPERT3",1,1,\ {"interplanetary medium","dust properties","comet trails"},\ {"Gr\"un,E.", "Salama,A.", "Sykes, M.", "Staude,J.", "Lemke,D.",\ "Abraham,P.", "Abolins,J."} <=== title ===> Properties of solar system dust, Section 3 <=== abstract ===> SCIENTIFIC ABSTRACT This proposal makes use of the opportunity given by ISO to study the properties fo the different dust populations in interplanetary space with the same instrument and identical observational procedures. For technical reasons, the properties of dust in comets and of asteroid surfacess are studied in separate central programme proposals, while this central programme proposal deals with - dust in the general interplanetary medium, - dust in the asteroidal bands, - dust in cometary trails. This procedure allows a thorough comparison of interplanetary dust with the properties of dust released from its probable sources, comets and asteroids, and thus contributes to the knowledge of the origin of interplanetary dust. OBSERVATION SUMMARY The properties of dust in the interplanetary medium, in asteroidal bands and in comet trails will be studied with ISOPHOT by the same type of measurements: photometry with ISOPHOT-P and ISOPHOT-C, either with full or with reduced spectral coverage, and spectrophotometry with ISOPHOT-S. In addition, scans perpendicular to the chosen asteroidal bands and comet trail will be performed to detect structure and to determine the position of maximum brightness for subsequent full photometry and spectrophotometry. For all measurements the largest aperture (180 arcsec) will be used. We aim at relative photometric accuracies of at least a few percent or better, which is needed to separate bands or trails from the much brighter background of zodiacal light. In spectrophotometry this accuracy will not be achieved for a single pixel. Here we take the longest available integration time and will improve the signal-to-noise ratio by binning. The proposal consists of three parts: 1. Dust in the general interplanetary medium 2. Asteroidal bands 3. Cometary trails Object lists and breakdown of observations by AOT's will be given in the three separate parts of this proposal. The common observing plan for photometry, spectrophotometry or scans will be given here. The choice of filters reflects the coordination with the proposals on "comets", "zodiacal light" and "extragalactic background light". Distribution of the observing times: Observations priority 1 priority 2 priority 3 sum ------------------------------------------------------------------ general medium 6478 s 15254 s 6478 s 28210 s asteroidal band 0 s 54369 s 0 s 54369 s cometary trail 24988 s 0 s 1859 s 26847 s ------------------------------------------------------------------ total 31466 s 69623 s 8337 s 109426 s (8.7 h) (19.3 h) (2.3 h) (30.4 h) 29 % 64 % 8 % === Detailed observing plan === 1. Full photometry Filter t(on object) t(performance) ---------------------------------------------- P_3.6 256 s 562 s P_4.85 64 s 180 s P_7.3 32 s 114 s P_10 32 s 110 s P_12.8 32 s 106 s P_11.5 32 s 98 s P_16 32 s 104 s P_25 32 s 198 s P_60 32 s 200 s P_100 32 s 202 s C_135 32 s 86 s C_160 32 s 76 s C_200 32 s 82 s Acquisition 180 s ------------------------------------------------- Performance time 2298 s (0.64 h) 2. Reduced photometry Filter t(on object) t(performance) ---------------------------------------------- P_7.3 32 s 114 s P_10 32 s 110 s P_12.8 32 s 106 s P_11.5 32 s 98 s P_16 32 s 104 s P_25 32 s 198 s P_60 32 s 200 s P_100 32 s 202 s C_160 32 s 76 s C_200 32 s 82 s Acquisition 180 s ------------------------------------------------- Performance time 1470 s (0.41 h) 3. Short photometry for scans Filter t(on object) t(performance) -------------------------------------------------------------------- P_12.8 4 s per raster point depends on scan type and length P_25 4 s per raster point depends on scan type and length P_60 4 s per raster point depends on scan type and length Acquisition 180 s per scan leg depends on number of legs 20 s per leg repetition depends on number of legs --------------------------------------------------------------- Performance time depends on scan length 4. Spectrophotometry Detector t(on object) t(performance) ---------------------------------------------------- SL 4096 s 4180 s SS 4096 s 0 s (parallel operation) Acquisition 0 s (already done) ---------------------------------------------------- Performance time 4180 s (1.2 h) === Special requirements === 1. It is the nature of the objects studied here that they are moving with the annual motion of the sun. This leads to the following consequences: a. FIXED TIME OBSERVATIONS are needed in several cases, because visibility and aspect conditions are only fulfilled around certain dates (defined by a value of lambda(sun), but also depending on launch date). These observations will be clearly indicated in the object lists of the three parts of this proposal. b. COORDINATES in alpha, delta can be provided for these moving objects, but only after more is known about lauch date and visibilities. Therefore they will not be given now but after the required information is available. c. Observations have to be performed at low background positions and at correct angles with respect to the sun. Even for non-fixed-time-observations strong constraints result, and we give PREFERRED TIME WINDOWS for the observations. d. For the observations of the comet trail we need the predicted position of the comet and the orientation of its trail for the date or dates of observation. 2. In contrast to most other observing programmes, the measurements of this proposal require absolute measurements. This needs both calibration and a knowledge of the dark current of the detectors for the integration times used. We assume, that - as part of the general calibration effort - DARK CURRENT MEASUREMENTS of sufficient quality will be available for the proposed measurements. <=== scientific_justification ===> Team top 40% middle 30% remaining 30% total performance time --------------------------------------------------------------------- PHOT 25160 s 51435 s 3612 s 80213 s SOT 6300 s 4725 s 4725 s 15750 s --------------------------------------------------------------------- Sum 31460 s 56160 s 8337 s 95963 s (8.7 h) (15.6 h) (2.3 h) (26.66 h) 33 % 59 % 9 % === Part 2: Asteroidal band - continued === These are linked fixed time observations. They consist of scans across the band, from which the position of maximum brightness has to be found. This position (default value |beta| = 10.0 deg, resp. =1.4 deg) is used in the following pointed observations. This constitutes the link. For both latitude ranges, |beta| about 10 deg and |beta| about 0 deg, the scans and the pointed observations have to be performed in one orbit each, and only a few orbits apart. Therefore they are declared as fixed-time observations, however with a time window of a few weeks given for their execution. === Object list === The list is given both for an autumn launch (30.11.95) and a spring launch (31.5.96). object (autumn) object (spring) Observations Priority ------------------------------------------------------------ ECLBAND-5_+5 ECLBAND-5_+5 slew scan 2 SLEWMAX1 SLEWMAX1 wideband photometry 2 SLEWMAX2 SLEWMAX2 wideband photometry 2 ECLBAND-5_-13 ECLBAND+5_+13 raster scan 2 ECL85,-5.0 ECL85,5.0 full photometry 2 spectrophotometry 2 ECL85,-7.0 ECL85,7.0 reduced photometry 2 ECL85,-9.0 ECL85,9.0 reduced photometry 2 ECL85,MAX- ECL85,MAX+ full photometry 2 spectrophotometry 2 ECL85,-11.0 ECL85.11.0 reduced photometry 2 ECL85,-13.0 ECL85.13.0 reduced photometry 2 ECL85,-15.0 ECL85,15.0 full photometry 2 ------------------------------------------------------------ RASTER SCAN DEFINITION: filter scan performance time ----------------------------------------------------------- initial acquisition: 180 s aquisition between concatenated legs : 5 x 20 s P_12.8 start |beta| = 5.0 6 x 669 s * with P05 step 3' (concatenated) * 29 positions end |beta| = 13.4 * overlap 1-3 points initial acquisition 180 s aquisition between concatenated legs : 5 x 20 s P_25 same but reverse 6 x 760 s initial acquisition 180 s aquisition between concatenated legs : 5 x 20 s P_60 same as P_12.8 6 x 762 s ----------------------------------------------------------- total 13986 s (3.9 h) SLEW SCAN DEFINITION filter slew performance time ----------------------------------------------------------- initial acquisition 180 s P_11.5 absolute measurement 98 s P_11.5 start beta = -5.0 616 s slew until end of beta = +5.0 initial acquisition 20 s P_25 same 198 s 716 s initial acquisition 20 s P_60 same 200 s 718 s ----------------------------------------------------------- total 2776 s (0.77 h) WIDEBAND PHOTOMETRY DEFINITION Filter t(on object) t(performance) S/N ------------------------------------------------- P_3.6 256 s 562 s 21 P_7.3 32 s 114 s 114 P_11.5 32 s 98 s 601 P_25 32 s 198 s 631 P_60 32 s 200 s 748 C_160 32 s 76 s 782 C_200 32 s 82 s 296 Acquisition 180 s ------------------------------------------------- Performance time 1510 s (0.42 h) POSITIONS: ECLBAND5_13 is a strip in a low background region at lambda = 20 deg for an autumn launch, around lambda = 150 deg for a spring launch, extending from beta = 5 deg to beta = 13 deg. The observations have to be performed at |lambda - lambda(sun)| approx.= 85 deg. Actually the scan along ECLBAND will be performed in 6 pieces, each about 1.4 deg long and overlapping by 9'. Similarly, ECLBAND-5_+5 is a 10 degree strip located symmetrically around the ecliptic. ECL "a","b" means a position on the sky with|lamba - lambda(sun)| = "a", beta = "b". The actual measurement has to be performed at a low background position. The actual value of beta is realised by a list of such low background positions provided by us. The actual value of |lambda - lambda>(sun)| is realised by the choice of observing period. VISIBILITIES: Visibilities lead to the following fixed time observation windows: for autumn launch --- orbits 160 - 220 approximately for spring launch --- orbits 160 - 220 approximately PERFORMANCE TIME: Priority 1 0 s Priority 2 40906 s (11.36 h) Priority 3 0 s -------------------------------------- Sum 40906 s (11.36 h) <=== autumn_launch_targets ===> 1, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 294, 2 2, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 110, 3 3, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 106, 4 4, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 98, 5 5, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 104, 6 6, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 198, 7 7, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 200, 8 8, "PHT05", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 202, 9 9, "PHT25", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 76, 10 10, "PHT25", 2.0, "N", "ECL85,-13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 82, 0 11, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 742, 12 12, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 180, 13 13, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 114, 14 14, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 110, 15 15, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 106, 16 16, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 98, 17 17, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 104, 18 18, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 198, 19 19, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 200, 20 20, "PHT05", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 202, 21 21, "PHT25", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 86, 22 22, "PHT25", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 76, 23 23, "PHT25", 2.0, "N", "ECL85,-15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 82, 0 <=== spring_launch_targets ===> 1, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 294, 2 2, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 110, 3 3, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 106, 4 4, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 98, 5 5, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 104, 6 6, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 198, 7 7, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 200, 8 8, "PHT05", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 202, 9 9, "PHT25", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 76, 10 10, "PHT25", 2.0, "N", "ECL85,13 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 82, 0 11, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 742, 12 12, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 180, 13 13, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 114, 14 14, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 110, 15 15, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 106, 16 16, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 98, 17 17, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 104, 18 18, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 198, 19 19, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 200, 20 20, "PHT05", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 202, 21 21, "PHT25", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 86, 22 22, "PHT25", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 76, 23 23, "PHT25", 2.0, "N", "ECL85,15 ", 0.00000, 0.00000, 2000, 0.000, 0.000, 82, 0