COVER INFORMATION Station: VLBA_HN (Code Hn ) Experiment: bw082 M87 movie pilot. Walker, Ly, Junor, Hardee Exp. Code: bw082b Schedule Version: 1.00 Processed by SCHED version: 6.04 March 2006 PI: R.C. Walker Address: NRAO, P.O. Box O Socorro, NM 87801 USA Phone: +1-505-835-7247 (w) / +1-505-835-3972 (h) EMAIL: cwalker@nrao.edu Fax: +1-505-835-7027 Phone during observation: +1-505-835-7247 (w) / +1-505-835-3972 (h) Observing mode: VLBA Notes: COVER LETTER: This 6 session project samples different possible frame rates for a 7mm movie of M87. It is needed prior to full movie observations because the rate of changes near the core is not known. It is likely that they have been severly undersampled by previous observations. Each session will use the same schedule. The sessions should fall in the following windows (days) after the first: 0, 3, 6, 12-16, 31-39, 80-100. The program committee has asked me to coordinate with Phillip Hicks on the scheduling. I will do so. I propose to use long range forcasts to identify a 6 day window in which to start, and then, at 12, 31, and 80 days, identify a day within the 5, 9, and 21 day windows that follow in which to do a session. Here is the key information from the time allocation email: ------------------ PROPOSAL STATUS ( 01/06/05 ): Approved for dynamic scheduling, high priority Proposal Selection Committee - December 3, 2004: We ask Phillip Hicks to seek permission from Craig Walker before starting the observing sequence, rather than having Phillip be responsible for making the long-term weather forecast. CURRENT TIME ALLOCATION: 6 times 10.0 hrs dynamically scheduled centered at LST 12.5 with 128 Mbits/sec recording --------------------- I apologize for the long delay in starting this project, but it will take my attention once started and, for personal reasons, I did not feel I was in a position to provide that over the last year. ------------------------------------------------------------------------- Schedule for VLBA_HN (Code Hn ) Page 2 bw082 M87 movie pilot. Walker, Ly, Junor, Hardee UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. For disks, the footages are really the GBytes TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Tue 11 Apr 2006 Day 101 --- Next scan frequencies: 43127.49 43127.49 43135.49 43135.49 Next BBC frequencies: 727.49 727.49 735.49 735.49 Next scan bandwidths: 8.00 8.00 8.00 8.00 01 25 57 OJ287 09 54 32 64.0 213.2 1.0 25.3 0 1 1 0 01 25 27 01 33 56 --- 10 02 32 63.1 217.0 1.1 28.0 479 F 1 8 01 25 50 01 36 00 3C274 10 04 36 46.0 122.9 -2.4 -39.0 55 1 1 8 01 35 30 01 50 58 --- 10 19 36 48.3 127.2 -2.2 -36.7 898 F 1 23 01 35 53 01 51 41 3C279 10 20 19 29.8 133.8 -2.6 -32.1 0 1 1 23 01 50 58 01 53 40 --- 10 22 19 30.0 134.3 -2.6 -31.8 120 F 1 26 01 50 58 01 54 24 3C274 10 23 03 48.8 128.2 -2.1 -36.1 0 1 1 26 01 53 40 02 09 21 --- 10 38 03 50.9 132.9 -1.9 -33.3 898 F 1 41 01 53 40 02 10 05 3C279 10 38 47 32.1 138.4 -2.3 -29.3 0 1 1 41 02 09 21 02 12 04 --- 10 40 47 32.4 138.9 -2.3 -28.9 120 F 1 44 02 09 21 02 12 48 3C274 10 41 31 51.3 134.0 -1.8 -32.6 0 1 1 44 02 12 04 02 27 46 --- 10 56 31 53.2 139.1 -1.6 -29.4 898 F 1 59 02 12 04 02 28 30 3C279 10 57 15 34.2 143.2 -2.0 -26.1 0 1 1 59 02 27 46 02 30 29 --- 10 59 15 34.5 143.8 -2.0 -25.8 120 F 1 61 02 27 46 02 31 14 3C274 10 59 59 53.6 140.4 -1.5 -28.6 0 1 1 61 02 30 29 02 46 11 --- 11 14 59 55.3 146.0 -1.3 -24.8 898 F 1 77 02 30 29 02 46 56 3C279 11 15 43 36.1 148.4 -1.7 -22.7 0 1 1 77 02 46 11 02 48 55 --- 11 17 43 36.3 148.9 -1.6 -22.3 120 F 1 79 02 46 11 02 49 40 3C274 11 18 28 55.6 147.4 -1.2 -23.8 0 1 1 79 02 48 55 03 04 37 --- 11 33 28 57.0 153.5 -1.0 -19.5 898 F 1 94 02 48 55 03 05 22 3C279 11 34 13 37.8 153.7 -1.4 -19.0 0 1 1 94 03 04 37 03 07 21 --- 11 36 13 37.9 154.3 -1.3 -18.6 120 F 1 97 03 04 37 03 08 06 3C274 11 36 57 57.2 155.0 -0.9 -18.5 0 1 1 97 03 07 21 03 23 03 --- 11 51 57 58.3 161.6 -0.7 -13.7 898 F 1 112 03 07 21 03 23 48 3C279 11 52 42 39.1 159.4 -1.1 -15.0 0 1 1 112 03 23 03 03 25 48 --- 11 54 42 39.3 160.0 -1.0 -14.6 120 F 1 115 03 23 03 Schedule for VLBA_HN (Code Hn ) Page 3 bw082 M87 movie pilot. Walker, Ly, Junor, Hardee UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. For disks, the footages are really the GBytes TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Tue 11 Apr 2006 Day 101 --- 03 26 32 3C274 11 55 26 58.5 163.1 -0.6 -12.5 0 1 1 115 03 25 48 03 41 30 --- 12 10 26 59.1 170.1 -0.3 -7.4 898 F 1 130 03 25 48 03 42 13 3C279 12 11 10 40.2 165.2 -0.8 -10.9 0 1 1 130 03 41 30 03 44 13 --- 12 13 10 40.3 165.8 -0.7 -10.4 120 F 1 133 03 41 30 03 46 13 OJ287 12 15 10 42.5 257.5 3.3 49.6 53 1 1 133 03 45 43 03 51 12 --- 12 20 10 41.6 258.5 3.4 49.8 299 F 1 138 03 46 06 03 53 02 J1159+2914 12 22 01 75.6 199.7 0.4 16.5 36 1 1 138 03 52 32 03 58 01 =1156+295 12 27 01 75.2 203.9 0.5 19.8 299 F 1 143 03 52 55 03 59 03 3C274 12 28 03 59.4 178.5 -0.1 -1.1 24 1 1 143 03 58 33 04 14 01 --- 12 43 03 59.3 185.7 0.2 4.3 898 F 1 158 03 58 56 04 14 45 3C279 12 43 47 41.2 175.8 -0.2 -3.1 2 1 1 158 04 14 01 04 16 45 --- 12 45 47 41.2 176.4 -0.2 -2.6 120 F 1 161 04 14 01 04 17 29 3C274 12 46 32 59.2 187.4 0.3 5.5 2 1 1 161 04 16 45 04 32 27 --- 13 01 32 58.7 194.4 0.5 10.7 898 F 1 176 04 16 45 04 33 11 3C279 13 02 16 41.2 181.9 0.1 1.4 3 1 1 176 04 32 27 04 35 11 --- 13 04 16 41.2 182.6 0.1 1.9 120 F 1 179 04 32 27 04 35 55 3C274 13 05 01 58.6 196.0 0.6 11.9 4 1 1 179 04 35 11 04 50 53 --- 13 20 01 57.6 202.7 0.8 16.8 898 F 1 194 04 35 11 04 51 37 3C279 13 20 45 40.9 188.0 0.4 5.9 5 1 1 194 04 50 53 04 53 37 --- 13 22 45 40.9 188.6 0.4 6.3 120 F 1 197 04 50 53 04 54 21 3C274 13 23 30 57.4 204.2 0.9 17.9 5 1 1 197 04 53 37 05 09 18 --- 13 38 30 56.1 210.5 1.1 22.4 898 F 1 212 04 53 37 05 10 02 3C279 13 39 14 40.3 194.0 0.7 10.2 6 1 1 212 05 09 18 05 12 02 --- 13 41 14 40.2 194.6 0.7 10.7 120 F 1 214 05 09 18 05 12 46 3C274 13 41 58 55.8 211.9 1.2 23.3 7 1 1 214 05 12 02 05 27 44 --- 13 56 58 54.2 217.7 1.4 27.3 898 F 1 230 05 12 02 05 28 28 3C279 13 57 42 39.3 199.8 1.0 14.5 8 1 1 230 05 27 44 05 30 28 --- 13 59 42 39.2 200.4 1.1 14.9 120 F 1 232 05 27 44 Schedule for VLBA_HN (Code Hn ) Page 4 bw082 M87 movie pilot. Walker, Ly, Junor, Hardee UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. For disks, the footages are really the GBytes TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Tue 11 Apr 2006 Day 101 --- 05 31 12 3C274 14 00 27 53.8 219.0 1.5 28.1 9 1 1 232 05 30 28 05 46 10 --- 14 15 27 52.0 224.2 1.7 31.5 898 F 1 248 05 30 28 05 46 54 3C279 14 16 11 38.0 205.5 1.3 18.5 10 1 1 248 05 46 10 05 48 54 --- 14 18 11 37.8 206.1 1.4 18.9 120 F 1 250 05 46 10 05 49 38 3C274 14 18 56 51.6 225.4 1.8 32.3 11 1 1 250 05 48 54 06 04 36 --- 14 33 56 49.5 230.2 2.0 35.2 898 F 1 265 05 48 54 06 05 20 3C279 14 34 41 36.4 210.9 1.6 22.2 12 1 1 265 06 04 36 06 07 20 --- 14 36 41 36.2 211.5 1.7 22.6 120 F 1 268 06 04 36 06 09 20 J1159+2914 14 38 41 55.5 259.8 2.6 55.6 75 1 1 268 06 08 50 06 14 19 =1156+295 14 43 41 54.6 260.9 2.7 55.9 299 F 1 273 06 09 13 06 16 20 J1310+3220 14 45 42 68.5 248.2 1.6 53.6 87 1 1 273 06 15 50 06 21 19 =1308+326 14 50 42 67.7 249.9 1.7 54.4 299 F 1 279 06 16 13 06 24 06 3C274 14 53 29 46.7 235.9 2.4 38.4 119 1 1 279 06 23 36 06 39 03 --- 15 08 29 44.3 240.0 2.6 40.5 898 F 1 294 06 23 59 06 39 48 3C279 15 09 14 32.7 220.3 2.2 28.4 15 1 1 294 06 39 03 06 41 47 --- 15 11 14 32.5 220.8 2.2 28.8 120 F 1 296 06 39 03 06 42 32 3C274 15 11 58 43.8 240.9 2.7 40.9 16 1 1 296 06 41 47 06 57 29 --- 15 26 58 41.3 244.6 2.9 42.6 898 F 1 311 06 41 47 06 58 13 3C279 15 27 42 30.4 225.0 2.5 31.4 16 1 1 311 06 57 29 07 00 13 --- 15 29 42 30.2 225.5 2.6 31.7 120 F 1 314 06 57 29 07 00 56 3C274 15 30 26 40.8 245.4 3.0 43.0 16 1 1 314 07 00 13 07 15 54 --- 15 45 26 38.2 248.8 3.2 44.3 898 F 1 329 07 00 13 07 16 36 3C279 15 46 08 27.9 229.4 2.8 34.0 16 1 1 329 07 15 54 07 18 36 --- 15 48 08 27.7 229.9 2.9 34.2 120 F 1 332 07 15 54 07 19 19 3C274 15 48 51 37.7 249.6 3.3 44.6 17 1 1 332 07 18 36 07 34 16 --- 16 03 51 35.1 252.8 3.5 45.7 898 F 1 347 07 18 36 07 34 58 3C279 16 04 33 25.3 233.6 3.1 36.3 16 1 1 347 07 34 16 07 36 58 --- 16 06 33 25.0 234.0 3.2 36.6 120 F 1 350 07 34 16 Schedule for VLBA_HN (Code Hn ) Page 5 bw082 M87 movie pilot. Walker, Ly, Junor, Hardee UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. For disks, the footages are really the GBytes TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Tue 11 Apr 2006 Day 101 --- 07 37 39 3C274 16 07 15 34.5 253.5 3.6 45.9 17 1 1 350 07 36 58 07 52 37 --- 16 22 15 31.8 256.5 3.9 46.8 898 F 1 365 07 36 58 07 53 17 3C279 16 22 56 22.5 237.6 3.4 38.4 16 1 1 365 07 52 37 07 55 17 --- 16 24 56 22.2 238.0 3.5 38.6 120 F 1 367 07 52 37 07 55 57 3C274 16 25 36 31.2 257.2 3.9 47.0 16 1 1 367 07 55 17 08 10 55 --- 16 40 36 28.5 260.0 4.2 47.6 898 F 1 382 07 55 17 08 11 34 3C279 16 41 15 19.6 241.4 3.7 40.2 16 1 1 382 08 10 55 08 13 34 --- 16 43 15 19.3 241.8 3.8 40.4 120 F 1 385 08 10 55 08 14 13 3C274 16 43 55 27.9 260.7 4.2 47.7 16 1 1 385 08 13 34 08 29 11 --- 16 58 55 25.2 263.4 4.5 48.1 898 F 1 400 08 13 34 08 29 49 3C279 16 59 34 16.7 245.0 4.1 41.8 16 1 1 400 08 29 11 08 31 49 --- 17 01 34 16.3 245.4 4.1 42.0 120 F 1 403 08 29 11 08 33 49 J1159+2914 17 03 34 29.2 284.1 5.1 54.4 88 1 1 403 08 33 19 08 38 48 =1156+295 17 08 34 28.3 284.8 5.1 54.2 299 F 1 408 08 33 42 08 39 25 J1310+3220 17 09 11 42.6 277.8 4.0 59.1 2 1 1 408 08 38 48 08 44 24 =1308+326 17 14 11 41.7 278.5 4.1 58.9 299 F 1 413 08 38 48 08 45 14 3C274 17 15 01 22.3 266.3 4.7 48.4 5 1 1 413 08 44 44 09 00 12 --- 17 30 01 19.5 268.9 5.0 48.5 898 F 1 428 08 45 07 09 00 54 3C279 17 30 44 11.4 250.8 4.6 44.0 20 1 1 428 09 00 12 09 02 54 --- 17 32 44 11.0 251.2 4.6 44.2 120 F 1 431 09 00 12 09 03 37 3C274 17 33 27 18.9 269.4 5.0 48.5 22 1 1 431 09 02 54 09 18 35 --- 17 48 27 16.2 272.0 5.3 48.5 898 F 1 446 09 02 54 09 19 19 3C279 17 49 11 8.2 254.1 4.9 45.1 22 1 1 446 09 18 35 09 21 19 --- 17 51 11 7.8 254.5 4.9 45.2 120 F 1 449 09 18 35 09 22 03 3C274 17 51 56 15.5 272.6 5.3 48.5 23 1 1 449 09 21 19 09 37 01 --- 18 06 56 12.8 275.1 5.6 48.3 898 F 1 464 09 21 19 09 37 44 3C279 18 07 40 4.9 257.4 5.2 H 45.9 22 1 1 464 09 37 01 09 39 44 --- 18 09 40 4.5 257.7 5.2 H 46.0 0 F 1 467 09 37 01 Schedule for VLBA_HN (Code Hn ) Page 6 bw082 M87 movie pilot. Walker, Ly, Junor, Hardee UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. For disks, the footages are really the GBytes TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Tue 11 Apr 2006 Day 101 --- 09 40 27 3C274 18 10 23 12.2 275.7 5.7 48.2 22 1 1 467 09 39 44 09 55 25 --- 18 25 23 9.4 278.2 5.9 47.9 898 F 1 482 09 39 44 09 58 42 3C274 18 28 41 8.8 278.7 6.0 47.8 191 1 1 482 09 58 12 10 13 40 --- 18 43 41 6.1 281.2 6.2 47.3 898 F 1 497 09 58 35 10 16 52 3C274 18 46 54 5.5 281.7 6.3 47.2 185 1 1 497 10 16 22 10 31 50 --- 19 01 54 2.9 284.2 6.5 H 46.6 0 F 1 512 10 16 45 10 35 02 3C274 19 05 07 2.3 284.8 6.6 H 46.4 186 1 1 512 10 34 32 10 50 00 --- 19 20 07 -0.3 287.3 6.8 D 45.7 0 F 1 527 10 34 55 11 13 18 1726+455 19 43 29 65.7 287.9 2.3 83.8 1266 1 1 527 11 12 48 11 16 18 --- 19 46 29 65.2 288.0 2.3 83.4 180 F 1 530 11 13 11 11 19 36 1751+288 19 49 48 62.8 248.2 1.9 50.9 165 1 1 530 11 19 06 11 22 35 --- 19 52 48 62.3 249.1 2.0 51.3 180 F 1 533 11 19 29 SETUP FILE INFORMATION: NOTE: If DOPPLER, FREQ, or BW were used, see the individual scans for the final BBC settings. Setup file: bw082.set Matches group v7mm_c8 in /home/arana/cwalker/sched/catalogs/freq.dat Setup group: 2 Station: VLBA_HN Total bit rate: 128 Format: VLBA1:4 Bits per sample: 2 Sample rate: 16.000 Number of channels: 4 Speedup factor: 2.00 Disk used to record data. 1st LO= 42400.00 42400.00 42400.00 42400.00 Net SB= U U U U Pol. = RCP LCP RCP LCP BBC = 1 2 3 4 BBC SB= U U U U IF = A C A C VLBA FE= 7mm omit 7mm omit VLBA Synth= 15.4 7.6 11.6 The following frequency sets based on this setup were used. Frequency Set: 2 Setup file default. Used pcal sets: 1 LO sum= 43127.49 43127.49 43135.49 43135.49 BBC fr= 727.49 727.49 735.49 735.49 Bandwd= 8.000 8.000 8.000 8.000 The following pulse cal sets were used with this setup: Pulse cal detection set: 1 PCAL = 1MHZ PCALXB1= S1 S3 S1 S3 S1 S2 S3 S4 PCALXB2= S2 S4 S2 S4 M1 M2 M3 M4 PCALFR1= 510 510 6510 6510 0 0 0 0 PCALFR2= 510 510 6510 6510 0 0 0 0 Track assignments are: track1= 2, 18, 3, 19 barrel=roll_off SOURCE LIST -- bw082 M87 movie pilot. Walker, Ly, Junor, Hardee Catalog positions marked with *. Precession of date coordinates is based on stop time of first scan. Names used in schedule marked with *. Short names used in VLA and SNAP files marked with +. Observation date used in B1950/J2000 coordinate conversion (PRECDATE): 1979.900 No adjustments are made for rates (DRA, DDEC). Scan hours are for recording scans only. Baseline hours are only counted for scans above horizon at both ends. Source Source position (RA/Dec) Error (B1950) (J2000) (Date) (mas) J0854+2006 08 51 57.250618 * 08 54 48.874930 08 55 10.932367 0.21 0851+202 20 17 58.41741 * 20 06 30.64086 20 05 09.97530 0.40 J0854+2006 /home/arana/cwalker/sched/catalogs/sources.vlba J0854+20 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro * OJ287 0.216 scan hours, 9.723 baseline hours above horizon. * J1159+2914 11 56 57.786209 * 11 59 31.833910 11 59 52.729654 0.23 1156+295 29 31 25.73874 * 29 14 43.82684 29 12 35.54423 0.40 J1159+29 /home/arana/cwalker/sched/catalogs/sources.vlba J1159+2914 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro J1159+2914 0.249 scan hours, 11.219 baseline hours above horizon. J1230+1223 12 28 17.569279 * 12 30 49.423381 12 31 09.757820 0.31 1228+126 12 40 01.74901 * 12 23 28.04383 12 21 16.34555 0.20 * 3C274 /home/arana/cwalker/sched/catalogs/sources.vlba J1230+12 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro J1230+1223 7.230 scan hours, 292.449 baseline hours above horizon. J1256-0547 12 53 35.831291 * 12 56 11.166559 12 56 31.754712 0.20 1253-055 -05 31 07.99586 *-05 47 21.52472 -05 49 33.01787 0.30 * 3C279 /home/arana/cwalker/sched/catalogs/sources.vlba J1256-05 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro J1256-0547 0.964 scan hours, 36.334 baseline hours above horizon. * J1310+3220 13 08 07.560131 * 13 10 28.663850 13 10 48.127739 0.24 1308+326 32 36 40.23883 * 32 20 43.78290 32 18 35.95428 0.40 J1310+32 /home/arana/cwalker/sched/catalogs/sources.vlba J1310+3220 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro J1310+3220 0.166 scan hours, 7.480 baseline hours above horizon. J1727+4530 17 26 01.198750 * 17 27 27.650804 17 27 39.423874 0.29 * 1726+455 45 33 04.55118 * 45 30 39.73133 45 29 55.47578 0.40 J1727+45 /home/arana/cwalker/sched/catalogs/sources.vlba J1727+4530 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro 0.050 scan hours, 2.244 baseline hours above horizon. J1753+2848 17 51 45.401869 * 17 53 42.473641 17 53 57.656264 0.23 * 1751+288 28 48 36.64959 * 28 48 04.93887 28 47 36.87293 0.40 J1753+28 /home/arana/cwalker/sched/catalogs/sources.vlba J1753+2848 VLBA Calib Survey - GSFC sols. - created L.Petrov 2005f_astro 0.050 scan hours, 2.244 baseline hours above horizon. The solar corona can cause unstable phases for sources too close to the Sun. SCHED provides warnings at individual scans for distances less than 10 degrees. The distance from the Sun to each source in this schedule is: Source Sun distance (deg) OJ287 109.3 J1159+2914 138.0 3C274 156.2 3C279 174.0 J1310+3220 139.4 1726+455 102.7 1751+288 104.1 Barry Clark estimates from predictions by Ketan Desai of IPM scattering sizes that the Sun will cause amplitude reductions on the longest VLBA baselines at a solar distance of 60deg F^(-0.6) where F is in GHz. For common VLBI bands, this is: 327 MHz 117. deg 610 MHz 81. deg 1.6 GHz 45. deg 2.3 GHz 36. deg 5.0 GHz 23. deg 8.4 GHz 17. deg 15.0 GHz 12. deg 22.0 GHz 9. deg 43.0 GHz 6. deg