1. POSSII IMAGES ASTROMÉTRIC REDUCTION Reduction methods and their influence on Theta and Rho measures Ignacio Novalbos O.A.N.L. Barcelona

2. O.A.N.L. Barcelona 2010 ORIGIN AND OBJECTIVE

3. O.A.N.L. Barcelona 2010 Relative astrometry of new pairs discovered on POSSII plates OAG Common Proper Motion Wide Pairs Survey ORIGIN

4. O.A.N.L. Barcelona 2010 OBJECTIVE Knowing which astrometric reduction method / software get the most accurate, when we measured on images from the POSSII-J, which usually present saturation for stars with magnitude <12.

5. O.A.N.L. Barcelona 2010 METHODOLOGY

6. METHODOLOGY - - Selection of pairs from the Catalog of Rectilinear Elements - - Getting POSS II images of each pair - - Get the time of each plate from the FITS header - - From the linear elements and using a linear regression we calculate the values for "x" and "y" - - From the rectangular coordinates we calculate polar coordinates (theta and rho), correcting the theta value for the quadrant - - We evaluate the accuracy of calculations by plotting “x / y “ vs epoch and " theta / rho” vs epoch, adjusting the values to a linear fit and analyzing the R-squared value - We confirm the accuracy of the estimates for theta and rho with the residuals obtained from the ephemerids calculated and those of the CRE - -We calculate the calibration constants for each of the plates from Astrométrica +USNO A2. - -Relative astrometry is obtained for each pair with different astrometric reduction methods - -We evaluate and compare the results

7. O.A.N.L. Barcelona 2010 PAIRS SELECTION

8. O.A.N.L. Barcelona 2010 CATALOG CATALOG Catalog Rectilinear Elements v. 2009.2 (1176 pairs)

9. O.A.N.L. Barcelona 2010 SELECTION CRITERIA - Pairs with Mag V>11 for both components. (61 Pairs = 5,2%) - Pairs with DEC between -20º y +20º. (15 Pairs = 1,3%) - Pairs with residuals <1º PA and < 0,5” Sep. (7 Pairs = 0,6%) - Pairs with rho >10”. (6 Pairs) - Pairs with historical measurements N >5. (6 Pairs)

10. O.A.N.L. Barcelona 2010 OBJECT PAIRS WDSIDR.A.DEC.NV1V2 CATALOG RECTILINEAR ELEMENTS EPHEMÉRIDS Épochtheta +/- rho +/- 00384+0130 BAL 947 00 38 23,51+01 30 11,81311,1011,242010.0216,60,318,9730,118 07140-0101 BAL 781 07 13 56,15 -01 01 26,6512,1512,222010.08,80,711,8590,139 14165+0145 H N 1AC 14 16 27,24+01 45 17,4811,3611,982010.0144,10,230,3770,128 17226+0410 BAL2891 17 22 33,51+04 09 51,71011,3911,532010.020,20,222,2850,219 22166+0147 HJ 3102 22 16 36,91+01 47 28,1911,0911,402010.0179,30,614,6280,202 23514+0225 HJ 3220 23 51 25,97+02 24 55,41211,3511,412010.011,10,536,3710,277

11. O.A.N.L. Barcelona 2010 IMAGES

12. POSS II-J

13. O.A.N.L. Barcelona 2010 OBSERVATORY Anglo-Australian Observatory

14. O.A.N.L. Barcelona 2010 TELESCOPE UK Schmidt Telescope

15. O.A.N.L. Barcelona 2010 PLATES PLATES BAL 947STScI_POSS2UKSTU_Red_00-38-24.00_+01-30-00.0 BAL 781STScI_POSS2UKSTU_Red_07-13-56.19_- 01-01-24.8 H N 1ACSTScI_POSS2UKSTU_Red_14-16-30.00_+01-45-00.0 BAL2891STScI_POSS2UKSTU_Red_17-22-36.00_+04-10-00.0 HJ 3102STScI_POSS2UKSTU_Red_22-16-36.00_+01-47-00.0 HJ 3220STScI_POSS2UKSTU_Red_23-51-24.00_+02-25-00.0

16. O.A.N.L. Barcelona 2010 STScI IMAGES BAL 781

17. O.A.N.L. Barcelona 2010 IMAGES ÉPOCH

18. O.A.N.L. Barcelona 2010 EPHEMERIDS CALCULATION EPHEMERIDS CALCULATION

19. O.A.N.L. Barcelona 2010 LINEAR ELEMENTS DDX0,,,,,,,,,XA,,,,,,,Y0,,,,,,,,,YA,,,,,,,T0,,,,,,RHO0,,,THETA0 +/-,,,,,,,,+/-,,,,,,+/-,,,,,,,,+/-,,,,,,+/-,,,,,+/-,,,,+/-,,, BAL 947 -2.664223-0.021999-1.3841880.0423421617.3873.002297.45 0.1938180.0005830.2063330.000620.010.1973.89 BAL 781 5.3102820.007829-1.8876780.0220252456.3695.63670.43 0.3826920.0007510.3583340.0007040.010.383.67 H N 1AC -5.9182520.04785915.5758430.0181851513.89916.662200.8 0.3076580.0006960.3243970.0007340.020.3221.07 BAL 2891 -6.1162680.053455-5.465692-0.0598181751.7138.203311.78 0.0637660.000320.2519540.0012650.010.1741.35 HJ 3102 -7.107194-0.0184796.003492-0.0218762404.2329.303229.81 0.250920.0005130.3331610.0006810.0090.2881.86 HJ 3220 21.087496-0.028467-13.20597-0.0454571515.29724.88157.94 0.4719820.0011760.3719120.0009270.0390.4460.93

20. O.A.N.L. Barcelona 2010 COORD. TRANSFORMATION We calculate the rectangular coordinates replacing in: x = xa * (t-t0) + x0 y = ya * (t-t0) + y0 From “x y” we obtain the polar coordinates replacing in: rho = Raiz(x^2 + y^2) theta = arctg (-y/x) Starting from the linear elements: (x0,y0,t0) (rho0,theta0,t0)

21. O.A.N.L. Barcelona 2010 LINEAR REGRESSION BAL 947 Correction 270º Catalog Ephemerids thetarho Époch (T) xy theta rhothetarho O-C 2010.0-11.3013163915.2398316553.44068498216.5618.973216.618.973-0.040.000 2009.5-11.2903168915.2186606553.42926971216.5718.949 2009.0-11.2793173915.1974896553.41782603216.5818.926 2008.5-11.2683178915.1763186553.40635383216.5918.902 2008.0-11.2573183915.1551476553.39485300216.6118.879 2007.5-11.2463188915.1339766553.38332343216.6218.855 2007.0-11.2353193915.1128056553.37176503216.6318.832 2006.5-11.2243198915.0916346553.36017767216.6418.808 2006.0-11.2133203915.0704636553.34856126216.6518.784 2005.5-11.2023208915.0492926553.33691569216.6618.761 2005.0-11.1913213915.0281216553.32524084216.6718.737216.718.738-0.03-0.001 2004.5-11.1803218915.0069506553.31353660216.6918.714

22. O.A.N.L. Barcelona 2010 LINEAR FIT “x”

23. O.A.N.L. Barcelona 2010 LINEAR FIT “y”

24. O.A.N.L. Barcelona 2010 LINEAR FIT “theta”

25. O.A.N.L. Barcelona 2010 LINEAR FIT “rho”

26. O.A.N.L. Barcelona 2010 ESTIMATED EPHEMERIDS Époch (T) Ephemerids PlatesxythetaCorrection ºthetarho BAL 947 1987.5-10.80633888714.287136646052.90270217.1017.914 BAL 781 1990.01.659079099-12.159455225082.23907.7712.272 HN 1AC 1994.017.05890175924.3064796850-54.9490144.9429.695 BAL 2891 1997.06.995548585-20.138269766070.849019.1621.319 HJ 3102 1990.50.53815962815.0542932320-87.9590177.9515.064 HJ 3220 1987.57.645293199-34.670901771077.569012.4435.504

27. O.A.N.L. Barcelona 2010 CALIBRATION CONSTANTS CALIBRATION CONSTANTS

28. O.A.N.L. Barcelona 2010 18:43:33 - USNO-A2.0: 154 Records read (22.8' x 22.8') Center Coordinates: RA = 00h 38m 24.00s, De = +01° 30' 00.0" Center Coordinates: RA = 00h 38m 24.00s, De = +01° 30' 00.0" 18:43:34 - Object List for Image 1 (BAL 947 STScI_POSS2UKSTU_Red_00-38-24.00_+01-30-00.0~1.fits): 753 Detections (75 Stars, 75 Ref. Stars, 0 Movers) 753 Detections (75 Stars, 75 Ref. Stars, 0 Movers) 18:43:34 - Astrometry of Image 1 (BAL 947 STScI_POSS2UKSTU_Red_00-38-24.00_+01-30-00.0~1.fits): 75 of 75 Reference Stars used: dRA = 0.36", dDe = 0.41" 75 of 75 Reference Stars used: dRA = 0.36", dDe = 0.41" X = +3.035090985E-6 +4.942446179E-6*x' +1.451099745E-8*y' X = +3.035090985E-6 +4.942446179E-6*x' +1.451099745E-8*y' Y = -3.718054588E-6 +1.501028067E-8*x' -4.946326400E-6*y' Y = -3.718054588E-6 +1.501028067E-8*x' -4.946326400E-6*y' Origin: x0 = 441.0, y0 = 441.0 Origin: x0 = 441.0, y0 = 441.0 Center Coordinates: RA = 00h 38m 23.96s, De = +01° 29' 59.2" Center Coordinates: RA = 00h 38m 23.96s, De = +01° 29' 59.2" Focal Length = 3033.7mm, Rotation = 0.17° Focal Length = 3033.7mm, Rotation = 0.17° Pixel Size: 1.02" x 1.02", Field of View: 15.0' x 15.0' Pixel Size: 1.02" x 1.02", Field of View: 15.0' x 15.0' 18:43:34 - Photometry of Image 1 (BAL 947 STScI_POSS2UKSTU_Red_00-38-24.00_+01-30-00.0~1.fits): 70 of 75 Reference Stars used: dmag = 0.41mag 70 of 75 Reference Stars used: dmag = 0.41mag CALIBRATION CONSTANTS

29. O.A.N.L. Barcelona 2010 CALIBRATION CONSTANTS Astrométrica + USNO-A2 AB A.Rotatión"/pixel R.A.DEC.R.A.DEC. BAL 947 +0,171.0200 38 23.550+01 30 13.4900 38 22.735+01 29 57.24 BAL 781 +0.081.0107 13 56.190-01 01 28.3407 13 56.209 -01 01 11.87 HN 1AC -0.091.0114 16 27.162+01 45 16.1614 16 28.470+01 44 52.06 BAL 2891 -0.181.0117 22 33.550+04 09 52.2617 22 34.013+04 10 12.43 HJ 3102 -0.091.0122 16 36.915+01 47 32.4322 16 36.924+01 47 12.75 HJ 3220 +0,131.0223 51 25.990+02 24 54.7823 51 26.404+02 25 29.42

30. O.A.N.L. Barcelona 2010 ASTROMETRY ASTROMETRY

31. O.A.N.L. Barcelona 2010 ABSOLUTE ASTROMETRY Astrométrica + USNO A-2

32. O.A.N.L. Barcelona 2010 RecToPol

33. RecToPol EfeméridesRecToPolO-C thetarhothetarhothetarho BAL 947 217.1017.914216.9520.3320.162.418 BAL 781 7.7712.2720.9916.4726.784.200 HN 1AC 144.9429.695140.8631.0714.071.376 BAL 2891 19.1621.31918.9521.3260.200.007 HJ 3102 177.9515.064179.6119.6801.654.616 HJ 3220 12.4435.50410.1635.1912.280.313 Desv. Estándar 2.541.945

34. O.A.N.L. Barcelona 2010 fv FITS VIEWER v 4.1.4

35. O.A.N.L. Barcelona 2010 fv FITS VIEWER v 4.1.4 EfeméridesfvO-C thetarhothetarhothetarho BAL 947 217.1017.914217.8317.9170.720.003 BAL 781 7.7712.2726.8812.6410.890.369 HN 1AC 144.9429.695144.6930.0520.240.356 BAL 2891 19.1621.31918.7521.5580.400.239 HJ 3102 177.9515.064177.5815.1060.370.042 HJ 3220 12.4435.50412.8035.5700.360.066 Desv Estándar 0.250.163

36. O.A.N.L. Barcelona 2010 ALADíN + “Dist”

37. O.A.N.L. Barcelona 2010 ALADíN + “Dist” EfeméridesAladínO-C thetarhothetarhothetarho BAL 947 217.1017.914217.0817.9140.020.000 BAL 781 7.7712.2727.6812.3100.090.038 HN 1AC 144.9429.695144.9229.7360.020.041 BAL 2891 19.1621.31919.2421.3880.080.069 HJ 3102 177.9515.064177.9014.9920.050.072 HJ 3220 12.4435.50412.5035.5700.060.066 Desv Estándar 0.030.028

38. O.A.N.L. Barcelona 2010 REDUC & SURFACE

39. O.A.N.L. Barcelona 2010 REDUC EfeméridesReducO-C thetarhothetarhothetarho BAL 947 217.1017.914217.2117.8240.110.090 BAL 781 7.7712.2727.9112.2080.140.064 HN 1AC 144.9429.695144.7829.7870.160.092 BAL 2891 19.1621.31919.3521.4080.190.089 HJ 3102 177.9515.064177.8315.1580.120.094 HJ 3220 12.4435.50412.4735.5220.030.018 Desv Estándar 0.050.030

40. O.A.N.L. Barcelona 2010 SURFACE EfeméridesSurfaceO-C thetarhothetarhothetarho BAL 947 217.1017.914216.6917.7500.410.164 BAL 781 7.7712.2727.2911.8900.480.382 HN 1AC 144.9429.695145.0129.2950.070.400 BAL 2891 19.1621.31918.9021.2380.260.081 HJ 3102 177.9515.064178.1415.3890.190.325 HJ 3220 12.4435.50412.7135.9060.270.402 Desv Estándar 0.150.137

41. O.A.N.L. Barcelona 2010 RESULTS RESULTS

42. O.A.N.L. Barcelona 2010 O-C THETA RecToPolfvAladínReducSurface BAL 947 0.160.720.020.110.41 BAL 781 6.780.890.090.140.48 HN 1AC 4.070.240.020.160.07 BAL 2891 0.200.400.080.190.26 HJ 3102 1.650.370.050.120.19 HJ 3220 2.280.360.060.030.27

43. O.A.N.L. Barcelona 2010 O-C THETA

44. O.A.N.L. Barcelona 2010 O-C THETA (2)

45. O.A.N.L. Barcelona 2010 O-C RHO RecToPolfvAladínReducSurface BAL 947 2.4180.0030.0000.0900.164 BAL 781 4.2000.3690.0380.0640.382 HN 1AC 1.3760.3560.0410.0920.400 BAL 2891 0.0070.2390.0690.0890.081 HJ 3102 4.6160.0420.0720.0940.325 HJ 3220 0.3130.066 0.0180.402

46. O.A.N.L. Barcelona 2010 O-C RHO

47. O.A.N.L. Barcelona 2010 O-C RHO (2)

48. O.A.N.L. Barcelona 2010 STANDARD DEVIATION O-C THETA/RHO

49. O.A.N.L. Barcelona 2010 CONCLUSIONS The largest deviations correspond to the results obtained with "RecToPol" which almost certainly is due to the low precision of Astrometrica in estimating the centroid for star-saturated images. The largest deviations correspond to the results obtained with "RecToPol" which almost certainly is due to the low precision of Astrometrica in estimating the centroid for star-saturated images. Residuals derived from measurements made with the software "fv" are 10 times better than those obtained from the absolute astrometry and we can accept them within the error margins normally allowed. Residuals derived from measurements made with the software "fv" are 10 times better than those obtained from the absolute astrometry and we can accept them within the error margins normally allowed. The measurements made with "Surface" improve even those obtained with "fv" and show theta and rho residuals in the order of tenths. The measurements made with "Surface" improve even those obtained with "fv" and show theta and rho residuals in the order of tenths. The two softwares / methods that presents the lowest residuals between observed and calculated ephemerids (and therefore the greatest accuracy available) are “Reduc" and the tool "Dist" from Aladin. The two softwares / methods that presents the lowest residuals between observed and calculated ephemerids (and therefore the greatest accuracy available) are “Reduc" and the tool "Dist" from Aladin.

50. O.A.N.L. Barcelona 2010 THE REASON? THE REASON? We conclude that eye and brain working in concert, we always give more accurate results than any other synthetic method based on mathematical calculations. The high precision of “Reduc", similar to that achieved manually with "Dist", we are pretty sure that is due to the "human component " that we put into the software when we mark the photocentric star manually. We conclude that eye and brain working in concert, we always give more accurate results than any other synthetic method based on mathematical calculations. The high precision of “Reduc", similar to that achieved manually with "Dist", we are pretty sure that is due to the "human component " that we put into the software when we mark the photocentric star manually.

51. O.A.N.L. Barcelona 2010