NICER observation list: Target ID 258401
- Proposal Number = 2584
- Target ID = 258401
- Target Name = SAX_J1808.4-3658
- Proposal Title = MONITORING THE ACCRETING MILLISECOND PULSAR SAX J1808.4-3658
- PI = PETER BULT
- Proposal Category = X-RAY PULSARS AND NEUTRON STARS
- Cycle number = 2
- Observation Type = NOR
Abstract
We propose to observe the next outburst of SAX J1808.4-3658 with NICER for a total exposure of 150 ks. Such an observation campaign will allow us to: 1) extend the pulsar timing baseline for this source to over 2 decades, giving the most precise measure yet of the long term spin and binary orbit evolution in an AMXP; 2) establish, for the first time, the systematic evolution of spectral and temporal variability in the soft emission over the course of an AMXP outburst; 3) achieve a high probability of observing type-I X-ray bursts and their potential interaction with the neutron star environment.
| Obsid |
RA |
DEC |
l |
b |
Start |
End |
Exposure |
Number of modules |
Status of Processing |
Date of Processing |
Public date |
| 2584010101 |
272.116 |
-36.978 |
355.38654 |
-8.14903 |
58703.7191 |
58703.9880 |
1695.00000 |
52 |
VALIDATED |
58707.7 |
58717 |
| 2584010102 |
272.115 |
-36.979 |
355.38522 |
-8.14819 |
58704.1068 |
58704.9553 |
1926.00000 |
52 |
VALIDATED |
58708.6 |
58718 |
| 2584010103 |
272.115 |
-36.979 |
355.38532 |
-8.14813 |
58705.0103 |
58705.9701 |
5485.00000 |
52 |
VALIDATED |
58709.6 |
58719 |
| 2584010104 |
272.114 |
-36.979 |
355.38475 |
-8.14798 |
58706.0266 |
58706.9542 |
3992.00000 |
52 |
VALIDATED |
58710.6 |
58720 |
| 2584010105 |
272.116 |
-36.978 |
355.38620 |
-8.14921 |
58706.9887 |
58707.9671 |
10628.00000 |
52 |
VALIDATED |
58711.8 |
58721 |
| 2584010106 |
272.116 |
-36.978 |
355.38610 |
-8.14872 |
58708.0199 |
58708.9984 |
12400.00000 |
52 |
VALIDATED |
58715.6 |
58722 |
| 2584010107 |
272.116 |
-36.979 |
355.38559 |
-8.14890 |
58709.1148 |
58709.9653 |
11582.34547 |
52 |
VALIDATED |
58715.6 |
58723 |
| 2584010108 |
272.115 |
-36.979 |
355.38545 |
-8.14860 |
58710.0183 |
58710.9970 |
11194.46965 |
52 |
VALIDATED |
58715.7 |
58724 |
| 2584010109 |
272.115 |
-36.979 |
355.38539 |
-8.14864 |
58711.0497 |
58711.9644 |
11630.00000 |
52 |
VALIDATED |
58715.8 |
58725 |
| 2584010110 |
272.115 |
-36.979 |
355.38534 |
-8.14857 |
58712.0171 |
58712.9965 |
13796.00000 |
52 |
VALIDATED |
58715.8 |
58726 |
| 2584010111 |
272.115 |
-36.979 |
355.38496 |
-8.14886 |
58729.8845 |
58729.9695 |
620.00000 |
52 |
VALIDATED |
58736.0 |
58743 |
| 2584010112 |
272.117 |
-36.981 |
355.38436 |
-8.15090 |
58730.0778 |
58730.5348 |
1271.00000 |
52 |
VALIDATED |
58736.1 |
58744 |
| 2584010201 |
272.115 |
-36.979 |
355.38536 |
-8.14838 |
58713.0007 |
58713.9641 |
13281.00000 |
52 |
VALIDATED |
58716.5 |
58727 |
| 2584010301 |
272.115 |
-36.979 |
355.38519 |
-8.14838 |
58714.0164 |
58714.9963 |
17552.00000 |
52 |
VALIDATED |
58992.0 |
58728 |
| 2584010401 |
272.115 |
-36.979 |
355.38526 |
-8.14835 |
58715.0041 |
58715.9815 |
16916.00000 |
52 |
VALIDATED |
58721.6 |
58729 |
| 2584010501 |
272.115 |
-36.979 |
355.38535 |
-8.14839 |
58716.0212 |
58716.9491 |
17618.00000 |
52 |
VALIDATED |
58721.7 |
58730 |
| 2584010502 |
272.115 |
-36.979 |
355.38531 |
-8.14850 |
58716.9898 |
58717.0134 |
1029.00000 |
52 |
VALIDATED |
58721.8 |
58731 |
| 2584010601 |
272.115 |
-36.979 |
355.38521 |
-8.14819 |
58717.0542 |
58717.9599 |
17169.00000 |
52 |
VALIDATED |
58721.8 |
58731 |
| 2584010701 |
272.115 |
-36.978 |
355.38579 |
-8.14825 |
58718.0152 |
58718.9493 |
10351.00000 |
52 |
VALIDATED |
58722.6 |
58732 |
| 2584010801 |
272.115 |
-36.979 |
355.38506 |
-8.14854 |
58718.9997 |
58719.9713 |
8753.00000 |
52 |
VALIDATED |
58723.6 |
58733 |
| 2584010901 |
272.115 |
-36.979 |
355.38468 |
-8.14847 |
58720.0311 |
58720.9488 |
5465.00000 |
52 |
VALIDATED |
58724.6 |
58734 |
| 2584011001 |
272.115 |
-36.979 |
355.38496 |
-8.14841 |
58721.0623 |
58721.9810 |
5850.00000 |
52 |
VALIDATED |
58729.9 |
58735 |
| 2584011101 |
272.115 |
-36.979 |
355.38478 |
-8.14859 |
58722.0303 |
58722.9421 |
14500.00000 |
52 |
VALIDATED |
58729.9 |
58736 |
| 2584011102 |
272.115 |
-36.979 |
355.38512 |
-8.14851 |
58722.9823 |
58723.0046 |
1265.00000 |
52 |
VALIDATED |
58730.0 |
58737 |
| 2584011201 |
272.115 |
-36.979 |
355.38501 |
-8.14829 |
58723.0459 |
58723.3808 |
3494.00000 |
52 |
VALIDATED |
58730.0 |
58737 |
| 2584011301 |
272.115 |
-36.979 |
355.38518 |
-8.14848 |
58724.2153 |
58724.4780 |
2298.00000 |
52 |
VALIDATED |
58730.1 |
58738 |
| 2584011401 |
272.115 |
-36.980 |
355.38439 |
-8.14916 |
58725.0461 |
58725.5794 |
3952.00000 |
52 |
VALIDATED |
58732.8 |
58739 |
| 2584011501 |
272.115 |
-36.979 |
355.38512 |
-8.14851 |
58726.2718 |
58726.6208 |
1542.00000 |
52 |
VALIDATED |
58732.9 |
58740 |
| 2584011502 |
272.117 |
-36.982 |
355.38330 |
-8.15109 |
58726.9806 |
58727.0012 |
840.00000 |
52 |
VALIDATED |
58735.8 |
58741 |
| 2584011601 |
272.118 |
-36.982 |
355.38357 |
-8.15167 |
58727.3030 |
58727.9611 |
1109.00000 |
52 |
VALIDATED |
58735.9 |
58741 |
| 2584011701 |
272.115 |
-36.979 |
355.38511 |
-8.14842 |
58728.0776 |
58728.6887 |
4309.00000 |
52 |
VALIDATED |
58735.9 |
58742 |
| 2584011702 |
272.115 |
-36.979 |
355.38514 |
-8.14841 |
58728.9803 |
58729.0111 |
1286.00000 |
52 |
VALIDATED |
58736.0 |
58743 |
| 2584011801 |
272.118 |
-36.982 |
355.38368 |
-8.15189 |
58729.2387 |
58729.4468 |
436.00000 |
52 |
VALIDATED |
58736.0 |
58743 |
| 2584011901 |
272.118 |
-36.982 |
355.38352 |
-8.15197 |
58730.5986 |
58730.8724 |
2169.00000 |
52 |
VALIDATED |
58736.1 |
58744 |
| 2584011902 |
272.115 |
-36.979 |
355.38505 |
-8.14890 |
58730.9953 |
58731.0014 |
0.00000 |
52 |
VALIDATED |
58736.6 |
58745 |
| 2584012001 |
272.115 |
-36.979 |
355.38479 |
-8.14886 |
58731.0479 |
58731.8421 |
5253.00000 |
52 |
VALIDATED |
58736.7 |
58745 |
| 2584012101 |
272.117 |
-36.980 |
355.38486 |
-8.15009 |
58732.0281 |
58732.9919 |
4436.00000 |
52 |
VALIDATED |
58736.7 |
58746 |
| 2584012102 |
272.115 |
-36.979 |
355.38457 |
-8.14843 |
58732.9950 |
58733.0051 |
179.00000 |
52 |
VALIDATED |
58737.7 |
58747 |
| 2584012201 |
272.115 |
-36.979 |
355.38515 |
-8.14858 |
58733.0448 |
58733.8944 |
2898.00000 |
52 |
VALIDATED |
58737.7 |
58747 |
| 2584012301 |
272.115 |
-36.979 |
355.38511 |
-8.14878 |
58734.0918 |
58734.9907 |
2579.00000 |
52 |
VALIDATED |
58738.6 |
58748 |
| 2584012401 |
272.115 |
-36.979 |
355.38514 |
-8.14886 |
58735.0586 |
58735.4491 |
764.00000 |
52 |
VALIDATED |
58739.6 |
58749 |
| 2584012501 |
272.114 |
-36.978 |
355.38549 |
-8.14732 |
58740.9111 |
58740.9810 |
606.00000 |
52 |
VALIDATED |
58745.7 |
58754 |
| 2584012601 |
272.114 |
-36.978 |
355.38573 |
-8.14719 |
58741.1043 |
58741.9525 |
1104.00000 |
52 |
VALIDATED |
58746.7 |
58755 |
| 2584012701 |
272.114 |
-36.978 |
355.38545 |
-8.14716 |
58742.0097 |
58742.9875 |
3289.00000 |
52 |
VALIDATED |
58746.8 |
58756 |
| 2584012801 |
272.115 |
-36.978 |
355.38567 |
-8.14777 |
58743.0417 |
58743.7000 |
4467.00000 |
52 |
VALIDATED |
58748.2 |
58757 |
| 2584012901 |
272.114 |
-36.978 |
355.38539 |
-8.14755 |
58744.1358 |
58744.9882 |
2675.00000 |
52 |
VALIDATED |
58749.6 |
58758 |
| 2584013001 |
272.114 |
-36.978 |
355.38544 |
-8.14698 |
58745.2970 |
58745.9618 |
3814.00000 |
52 |
VALIDATED |
58750.7 |
58759 |
| 2584013101 |
272.112 |
-36.977 |
355.38575 |
-8.14510 |
58746.2004 |
58746.9818 |
1704.00000 |
52 |
VALIDATED |
58750.7 |
58760 |
| 2584013201 |
272.115 |
-36.979 |
355.38533 |
-8.14795 |
58747.0386 |
58747.2440 |
2722.00000 |
52 |
VALIDATED |
58992.0 |
58761 |
| 2584013301 |
272.114 |
-36.978 |
355.38601 |
-8.14713 |
58748.5220 |
58748.9933 |
7124.00000 |
52 |
VALIDATED |
58752.9 |
58762 |
| 2584013401 |
272.113 |
-36.977 |
355.38605 |
-8.14585 |
58749.0385 |
58749.9454 |
7811.00000 |
52 |
VALIDATED |
58753.6 |
58763 |
| 2584013501 |
272.113 |
-36.977 |
355.38577 |
-8.14609 |
58750.2643 |
58750.9177 |
1811.00000 |
52 |
VALIDATED |
58754.6 |
58764 |
| 2584013601 |
272.113 |
-36.977 |
355.38611 |
-8.14627 |
58751.1027 |
58751.3052 |
1531.00000 |
52 |
VALIDATED |
58756.8 |
58765 |
| 2584013701 |
272.115 |
-36.978 |
355.38566 |
-8.14804 |
58752.0125 |
58752.9891 |
4544.00000 |
52 |
VALIDATED |
58756.8 |
58766 |
| 2584013801 |
272.113 |
-36.976 |
355.38705 |
-8.14532 |
58753.1029 |
58753.8857 |
5347.00000 |
52 |
VALIDATED |
58760.7 |
58767 |
| 2584013901 |
272.114 |
-36.977 |
355.38616 |
-8.14724 |
58754.1999 |
58754.7892 |
696.00000 |
52 |
VALIDATED |
58763.7 |
58768 |
| 2584014001 |
272.117 |
-36.982 |
355.38325 |
-8.15103 |
58765.1942 |
58765.4012 |
2396.00000 |
52 |
VALIDATED |
58770.9 |
58779 |
| 2584014002 |
272.117 |
-36.977 |
355.38730 |
-8.14908 |
58778.5404 |
58778.8736 |
0.00000 |
52 |
VALIDATED |
58782.7 |
58792 |
| 2584014101 |
272.118 |
-36.982 |
355.38371 |
-8.15151 |
58766.0323 |
58766.1757 |
2456.00000 |
52 |
VALIDATED |
58771.0 |
58780 |
| 2584014102 |
272.116 |
-36.978 |
355.38621 |
-8.14911 |
58779.3777 |
58779.7778 |
0.00000 |
52 |
VALIDATED |
58783.6 |
58793 |
| 2584014201 |
272.118 |
-36.980 |
355.38516 |
-8.15084 |
58768.0958 |
58768.9400 |
6040.00000 |
52 |
VALIDATED |
58778.8 |
58782 |
| 2584014202 |
272.116 |
-36.979 |
355.38574 |
-8.14872 |
58780.4099 |
58780.6803 |
0.00000 |
52 |
VALIDATED |
58784.7 |
58794 |
| 2584014301 |
272.119 |
-36.981 |
355.38482 |
-8.15220 |
58768.9991 |
58769.4637 |
3071.00000 |
52 |
VALIDATED |
58992.1 |
58783 |
| 2584014302 |
272.115 |
-36.979 |
355.38534 |
-8.14867 |
58781.3129 |
58781.9056 |
0.00000 |
52 |
VALIDATED |
58786.7 |
58795 |
| 2584014401 |
272.116 |
-36.979 |
355.38541 |
-8.14881 |
58782.0224 |
58782.4215 |
0.00000 |
52 |
VALIDATED |
58786.8 |
58796 |
| 2584014501 |
272.115 |
-36.979 |
355.38545 |
-8.14843 |
58784.5372 |
58784.8079 |
0.00000 |
50 |
VALIDATED |
58789.8 |
58798 |
| 2584014601 |
272.115 |
-36.979 |
355.38512 |
-8.14842 |
58786.2790 |
58786.4854 |
0.00000 |
50 |
VALIDATED |
58790.9 |
58800 |
| 2584014701 |
272.115 |
-36.979 |
355.38519 |
-8.14820 |
58788.8102 |
58788.9542 |
263.00000 |
50 |
VALIDATED |
58793.7 |
58802 |
| 2584014801 |
272.115 |
-36.979 |
355.38521 |
-8.14837 |
58789.0058 |
58789.0188 |
0.00000 |
50 |
VALIDATED |
58795.1 |
58803 |
| 2584014901 |
272.115 |
-36.979 |
355.38529 |
-8.14833 |
58790.3417 |
58790.4377 |
874.00000 |
50 |
VALIDATED |
58795.3 |
58804 |
| 2584014902 |
272.115 |
-36.979 |
355.38537 |
-8.14837 |
58792.5350 |
58792.6310 |
849.00000 |
50 |
VALIDATED |
58797.0 |
58806 |
| 2584015001 |
272.115 |
-36.979 |
355.38519 |
-8.14838 |
58793.5025 |
58793.5343 |
434.00000 |
49 |
VALIDATED |
58800.0 |
58807 |
| 2584015101 |
272.115 |
-36.979 |
355.38522 |
-8.14855 |
58795.1800 |
58795.2032 |
0.00000 |
49 |
VALIDATED |
58801.1 |
58809 |