# Subaru Telescope Optical Tertiary Mirror In-Situ Measured Reflectivity # Coated with Aluminum on 2025-12-16 # Opened the vacuum chamber: No information # Measured with Subaru Portable Spectrophotometer (SPS) on 2025-12-17 (1 days after) # Measured four times # Data between 950 nm and 1650 nm are also available (SPS-XWW). # Contact: Hirofumi Okita (okita14@naoj.org) # # Wavelength (nm) #1 #2 #3 #4 1000 93.02 92.16 93.14 92.09 998 92.89 92.53 93.17 92.43 996 92.23 92.46 92.90 92.68 994 92.01 92.22 92.66 92.18 992 92.36 92.13 92.28 92.78 990 92.27 91.36 92.75 91.53 988 92.40 92.25 91.80 92.32 986 92.28 92.16 92.29 91.29 984 92.93 92.84 93.63 92.62 982 91.96 91.94 91.54 92.08 980 92.12 91.49 92.54 92.59 978 92.85 91.84 92.35 91.40 976 92.86 90.95 92.19 92.06 974 91.89 92.13 92.39 92.40 972 91.95 91.37 91.95 91.41 970 91.76 91.95 91.18 91.71 968 92.33 92.00 91.76 91.85 966 92.02 91.51 91.40 91.60 964 91.74 91.21 92.04 91.90 962 92.25 92.17 91.67 92.30 960 91.92 91.68 91.57 92.13 958 91.41 92.23 91.81 91.64 956 90.60 91.75 91.46 90.73 954 91.62 90.97 91.32 91.01 952 91.51 91.46 91.58 91.70 950 91.33 91.66 90.87 90.79 948 90.89 91.30 91.37 90.55 946 90.23 91.15 91.25 90.62 944 90.88 91.16 90.96 90.71 942 90.65 91.26 90.88 90.86 940 90.17 91.01 90.89 90.69 938 90.36 91.59 91.12 90.56 936 90.59 90.45 90.95 90.17 934 90.61 91.03 90.52 89.85 932 90.55 90.85 91.11 89.91 930 90.48 90.62 90.17 89.83 928 90.06 90.46 89.91 90.27 926 89.89 89.84 89.94 89.75 924 89.97 90.24 90.17 89.59 922 90.33 90.13 90.37 89.63 920 89.60 89.84 89.67 90.18 918 89.95 89.60 89.96 89.77 916 89.31 89.53 90.38 89.35 914 89.83 89.29 89.64 89.19 912 89.18 89.29 89.66 89.59 910 89.05 89.24 89.77 88.49 908 89.22 89.55 89.32 89.00 906 88.67 88.95 89.28 88.93 904 89.07 89.16 89.00 89.09 902 88.74 88.55 89.13 89.08 900 88.34 88.92 88.88 88.62 898 88.35 88.66 88.88 88.73 896 88.44 88.58 88.85 88.34 894 88.30 88.44 88.20 87.92 892 87.87 88.19 88.50 88.17 890 87.83 87.93 88.01 87.75 888 87.72 87.96 87.97 87.78 886 87.88 87.56 88.26 87.46 884 87.95 87.70 87.57 87.51 882 87.25 87.58 87.51 87.49 880 87.74 87.21 87.47 87.59 878 87.52 87.41 87.39 87.31 876 87.02 87.45 87.45 87.50 874 86.95 87.13 87.17 86.97 872 86.83 87.19 86.97 86.68 870 86.53 87.25 87.07 86.77 868 86.87 86.42 87.07 86.29 866 86.55 86.77 86.96 86.31 864 86.09 86.52 86.59 86.02 862 86.50 86.77 86.66 86.22 860 86.36 86.33 86.68 85.96 858 86.18 86.05 86.48 85.96 856 86.12 86.31 86.25 85.97 854 85.49 86.21 86.15 85.96 852 86.01 86.23 86.21 85.96 850 85.71 86.08 85.82 85.86 848 86.06 86.28 86.32 85.45 846 85.93 85.56 86.00 86.07 844 85.70 85.91 86.00 85.13 842 85.22 85.58 85.69 85.22 840 85.59 85.45 85.25 85.36 838 85.27 85.52 85.61 85.17 836 85.57 85.53 85.49 84.91 834 85.26 85.45 85.63 85.38 832 85.30 85.52 85.59 85.28 830 85.19 85.61 85.45 85.60 828 85.06 85.53 85.33 85.13 826 85.27 85.34 85.40 85.02 824 85.06 85.55 85.31 85.61 822 85.04 86.22 85.46 85.29 820 85.30 85.52 85.63 85.62 818 85.62 85.00 85.25 84.84 816 85.17 85.12 85.45 85.09 814 85.09 85.63 85.32 85.08 812 85.08 85.17 85.14 85.24 810 85.02 85.24 85.10 85.00 808 85.29 85.59 85.56 85.30 806 85.33 85.48 85.59 85.32 804 85.25 85.42 85.36 85.68 802 85.48 85.51 85.58 85.52 800 85.55 85.73 85.42 85.39 798 85.59 85.33 85.34 85.21 796 85.45 85.66 85.93 85.55 794 85.43 85.53 85.63 85.54 792 85.42 85.62 86.08 85.33 790 85.86 85.97 85.90 85.29 788 85.78 86.01 86.18 85.66 786 85.92 85.75 86.07 85.88 784 85.37 86.07 86.14 85.79 782 85.76 85.73 86.23 85.76 780 85.84 85.90 86.45 85.84 778 86.45 86.14 86.07 85.92 776 86.15 86.32 86.10 85.77 774 85.94 86.25 86.31 85.73 772 86.01 86.38 86.48 85.88 770 86.40 86.13 86.36 85.97 768 86.19 86.57 86.61 86.04 766 86.16 86.50 86.57 86.24 764 86.34 86.39 86.76 86.11 762 86.26 86.40 86.75 86.38 760 86.71 86.66 86.75 86.20 758 86.43 86.72 86.70 86.53 756 86.74 86.82 86.98 86.30 754 86.83 86.74 87.07 86.48 752 86.86 86.84 86.98 86.38 750 86.80 86.64 87.17 86.33 748 87.36 86.91 87.15 86.61 746 86.70 87.28 87.47 86.86 744 87.21 87.07 87.25 86.94 742 86.86 87.13 87.31 86.80 740 87.21 87.11 87.31 86.89 738 87.08 87.27 87.28 87.18 736 86.92 87.42 87.25 87.26 734 87.19 87.56 87.24 87.13 732 87.19 87.23 87.47 87.20 730 87.24 87.60 87.54 87.18 728 87.18 87.65 87.68 87.06 726 87.36 87.54 87.84 87.31 724 87.39 87.49 87.81 87.30 722 87.64 87.66 87.60 87.35 720 87.29 87.66 87.76 87.47 718 87.59 87.77 87.68 87.38 716 87.42 88.02 87.84 87.60 714 87.32 87.91 87.69 87.56 712 87.59 87.80 87.98 87.49 710 87.80 87.93 87.97 87.57 708 87.73 88.47 88.21 87.57 706 87.96 88.00 87.94 87.54 704 87.92 88.07 88.04 87.79 702 87.70 88.09 88.16 87.62 700 87.96 88.09 88.19 87.91 698 87.89 88.13 88.24 87.68 696 88.20 88.27 88.35 87.62 694 87.98 88.36 88.18 88.16 692 87.88 88.30 88.05 87.97 690 88.10 88.27 88.16 87.62 688 87.92 88.41 88.21 88.21 686 88.14 88.40 88.44 88.23 684 88.04 88.30 88.49 88.13 682 87.93 88.39 88.61 87.95 680 88.10 88.26 88.57 88.24 678 88.22 88.67 88.57 88.15 676 88.09 88.54 88.46 88.09 674 88.12 88.54 88.59 88.25 672 88.33 88.73 88.69 88.21 670 88.52 88.58 88.65 88.07 668 88.53 88.70 88.50 88.26 666 88.55 88.71 88.71 88.38 664 88.43 88.69 88.48 88.33 662 88.43 88.73 88.83 88.35 660 88.66 88.52 88.83 88.53 658 88.55 88.67 88.76 88.41 656 88.66 88.76 88.86 88.48 654 88.66 88.81 88.68 88.46 652 88.49 88.84 88.70 88.48 650 88.69 88.80 88.83 88.66 648 88.44 88.92 88.99 88.59 646 88.68 89.11 89.01 88.50 644 88.75 88.90 89.09 88.48 642 88.70 88.92 89.02 88.72 640 88.56 88.93 88.84 88.71 638 88.56 89.12 89.01 88.71 636 88.74 89.02 88.94 88.63 634 88.75 89.05 89.13 88.91 632 88.71 89.10 88.99 88.65 630 88.94 89.08 88.92 88.91 628 88.78 89.23 89.16 88.84 626 88.92 88.79 89.03 88.87 624 88.76 89.39 89.06 88.87 622 88.95 89.16 89.35 88.92 620 89.03 89.08 89.20 88.97 618 88.76 89.17 89.27 89.04 616 88.84 89.16 89.09 88.84 614 88.91 89.11 89.18 88.88 612 88.89 89.37 89.44 88.87 610 88.96 89.32 89.40 88.92 608 89.08 89.33 89.32 88.91 606 89.13 89.15 89.34 89.00 604 89.00 89.50 89.32 88.51 602 89.02 89.34 89.30 88.57 600 89.09 89.50 89.41 88.95 598 89.19 89.40 89.49 89.09 596 89.19 89.67 89.45 89.06 594 89.16 89.40 89.31 89.23 592 89.08 89.37 89.37 89.02 590 89.19 89.46 89.38 89.24 588 89.24 89.60 89.56 89.11 586 89.23 89.46 89.38 89.33 584 89.10 89.36 89.91 89.37 582 89.07 89.38 89.50 89.24 580 89.26 89.63 89.43 89.18 578 89.15 89.56 89.55 88.99 576 89.28 89.52 89.65 89.28 574 89.26 89.52 89.49 89.11 572 89.33 89.76 89.38 89.42 570 89.23 89.48 89.56 89.20 568 89.40 89.77 89.52 89.23 566 89.17 89.56 89.56 89.44 564 89.29 89.49 89.58 89.25 562 89.25 89.65 89.55 89.23 560 89.27 89.61 89.52 89.28 558 89.27 89.46 89.71 89.38 556 89.29 89.55 89.64 89.20 554 89.52 89.65 89.56 89.22 552 89.48 89.73 89.63 89.39 550 89.45 89.83 89.53 89.23 548 89.29 89.60 89.48 89.19 546 89.43 89.55 89.71 89.35 544 89.21 89.74 89.72 89.27 542 89.70 89.62 89.71 89.55 540 89.55 89.57 89.80 89.28 538 89.23 89.63 89.83 89.48 536 89.38 89.65 90.06 88.92 534 89.27 89.81 90.00 89.52 532 89.61 89.71 89.75 89.39 530 89.57 89.90 89.96 89.43 528 89.52 89.65 89.86 89.52 526 89.45 89.85 89.63 89.54 524 89.54 90.00 89.61 89.49 522 89.13 89.84 89.72 89.44 520 89.52 90.02 89.88 89.48 518 89.48 89.96 89.85 89.72 516 89.23 90.01 89.55 89.39 514 89.58 89.77 89.80 89.57 512 89.32 89.85 89.75 89.44 510 89.61 90.00 89.74 89.54 508 89.50 89.86 89.67 89.49 506 89.48 89.81 89.83 89.65 504 89.44 89.64 89.74 89.33 502 89.64 89.89 89.88 89.52 500 89.32 89.70 89.91 89.69 498 89.27 89.73 89.88 89.58 496 89.40 89.85 89.75 89.55 494 89.35 89.73 89.80 89.70 492 89.61 89.71 89.61 89.72 490 89.47 90.03 89.72 89.39 488 89.52 89.63 89.59 89.72 486 89.43 89.84 90.09 89.53 484 89.88 90.01 89.88 89.61 482 89.66 89.76 89.90 89.52 480 89.49 89.72 89.79 89.40 478 89.44 89.99 89.57 89.45 476 89.38 89.73 89.80 89.47 474 89.46 89.76 89.74 89.51 472 89.68 89.62 89.82 89.74 470 89.86 90.02 89.66 89.40 468 89.48 90.37 89.87 89.85 466 89.65 90.02 89.94 89.65 464 89.47 89.57 89.71 89.54 462 89.58 89.90 89.60 89.93 460 89.63 90.10 89.89 89.80 458 89.95 89.76 89.55 89.63 456 89.82 89.82 89.77 89.62 454 89.48 89.77 89.95 89.66 452 89.51 89.85 90.02 89.95 450 89.72 89.96 89.57 89.36 448 89.39 90.01 90.06 89.52 446 89.47 89.91 90.02 89.57 444 89.70 89.93 90.04 89.53 442 89.34 89.65 89.88 90.09 440 89.48 89.83 89.85 89.77 438 88.85 89.83 89.84 89.48 436 89.53 89.90 89.84 90.19 434 89.75 89.58 89.97 89.59 432 89.36 89.80 89.88 90.08 430 89.56 89.42 90.30 90.00 428 89.31 89.99 89.91 89.80 426 89.65 90.22 90.27 89.68 424 89.24 89.94 90.20 89.91 422 89.50 89.69 89.58 89.88 420 90.08 89.83 89.49 89.50 418 90.01 89.98 89.74 89.95 416 89.73 90.45 89.57 89.47 414 89.35 90.07 89.81 89.28 412 89.82 89.44 90.17 89.53 410 89.73 89.59 89.90 89.69 408 89.28 89.67 89.82 89.64 406 88.70 89.55 89.73 89.14 404 89.27 90.09 89.23 90.05 402 89.19 90.49 89.58 89.57 400 89.78 90.55 89.52 89.26 398 89.80 89.34 89.24 88.65 396 90.30 89.53 89.97 89.09 394 90.07 88.91 89.47 89.13 392 88.97 89.45 89.78 90.63 390 89.62 90.33 89.01 89.64 388 89.64 90.13 89.85 89.19 386 88.93 89.52 90.03 89.79 384 88.26 88.69 89.94 89.64 382 89.35 88.78 88.61 89.94 380 89.70 89.42 91.49 90.26 1650 96.62 96.62 96.66 96.46 1640 96.62 96.63 96.66 96.43 1630 96.61 96.63 96.67 96.46 1620 96.63 96.63 96.66 96.46 1610 96.61 96.63 96.66 96.45 1600 96.61 96.62 96.66 96.45 1590 96.60 96.63 96.65 96.42 1580 96.59 96.61 96.64 96.42 1570 96.59 96.62 96.64 96.41 1560 96.57 96.60 96.62 96.40 1550 96.57 96.58 96.62 96.38 1540 96.57 96.57 96.59 96.36 1530 96.53 96.55 96.60 96.35 1520 96.51 96.55 96.58 96.33 1510 96.50 96.53 96.56 96.32 1500 96.49 96.50 96.54 96.30 1490 96.46 96.49 96.53 96.28 1480 96.44 96.46 96.50 96.26 1470 96.42 96.45 96.50 96.24 1460 96.40 96.43 96.47 96.22 1450 96.39 96.41 96.46 96.18 1440 96.35 96.40 96.43 96.17 1430 96.34 96.37 96.41 96.14 1420 96.31 96.35 96.39 96.11 1410 96.29 96.33 96.36 96.07 1400 96.26 96.31 96.34 96.05 1390 96.24 96.28 96.32 96.01 1380 96.21 96.25 96.28 95.99 1370 96.18 96.22 96.26 95.97 1360 96.15 96.20 96.24 95.94 1350 96.13 96.16 96.20 95.92 1340 96.10 96.13 96.17 95.89 1330 96.06 96.11 96.15 95.85 1320 96.03 96.08 96.11 95.83 1310 95.99 96.05 96.08 95.78 1300 95.96 96.02 96.04 95.75 1290 95.92 95.98 96.01 95.72 1280 95.89 95.94 95.97 95.67 1270 95.85 95.90 95.94 95.63 1260 95.81 95.87 95.88 95.60 1250 95.77 95.82 95.85 95.57 1240 95.72 95.78 95.81 95.50 1230 95.67 95.73 95.75 95.46 1220 95.61 95.70 95.72 95.41 1210 95.56 95.64 95.65 95.35 1200 95.51 95.58 95.60 95.29 1190 95.45 95.52 95.54 95.24 1180 95.38 95.46 95.48 95.17 1170 95.32 95.40 95.41 95.10 1160 95.26 95.33 95.35 95.02 1150 95.18 95.27 95.27 94.96 1140 95.11 95.18 95.19 94.87 1130 95.02 95.11 95.11 94.80 1120 94.92 95.02 95.02 94.71 1110 94.82 94.91 94.92 94.60 1100 94.73 94.81 94.83 94.50 1090 94.62 94.72 94.72 94.39 1080 94.48 94.59 94.59 94.28 1070 94.35 94.46 94.46 94.14 1060 94.21 94.33 94.34 94.00 1050 94.07 94.17 94.16 93.85 1040 93.89 93.99 94.00 93.68 1030 93.72 93.83 93.83 93.51 1020 93.50 93.63 93.62 93.29 1010 93.30 93.42 93.42 93.09 1000 93.07 93.19 93.17 92.85 990 92.79 92.92 92.93 92.59 980 92.50 92.63 92.62 92.30 970 92.17 92.34 92.31 91.98 960 91.84 91.99 91.97 91.65 950 91.45 91.59 91.58 91.26