5. Light curve variation

In addition to our own light curves, we compiled all other published light curves from the literature, and plotted them on the same scale by using different symbols for different night's observations.

  
Figure 4: The best sinusoidal fitting curve superimposed on the () diagram

All observations cover the interval between 1958 and 1994. A list and short information is given in Table 6 (click here) about the available light curves of V 839 Oph. To examine long-term light variation on these curves, we read the light levels at maximum and minimum to form the magnitude differences , , and the depths of the minimum D_1,2 for every light curve, where

and

The values for these four parameters in the V filter are listed in Table 6 (click here) and displayed in Fig. 5 (click here). The full amplitude of the irregular variations of the four quantities is always less than showing that no significant long term variations are detected in these four quantities. Due to insufficient and very unevenly distributed data points in Fig. 5 no conclusion can be drawn yet about the long-term light variations. Only systematic and continuous observations may help to decide on the existence of general trends in the variations of light levels and depths of the minima.

  
Figure 5: The change of the , , D₁ and D₂ describing the long-term behaviour of the light levels of V 839 Oph (see text)

 

HJD Min Type Method E Source (2400000+)

31587.7617 2 v -43884.5 -0.07478 -0.01649 -0.01353 1

36361.7317 1 pe -32212.0 -0.10265 0.00704 0.00116 2

36734.7347 1 pe -31300.0 -0.10335 0.00837 0.00266 2

36735.7574 2 pe -31297.5 -0.10319 0.00854 0.00283 2

37424.9147 2 peB -29612.5 -0.10302 0.01170 0.00780 3

42241.4440 1 v -17836.0 -0.10707 0.00103 -0.00068 4

42251.4630 2 v -17811.5 -0.10846 -0.00042 -0.00218 4

42267.4060 2 v -17772.5 -0.11628 -0.00834 -0.01018 5

42272.5480 1 v -17760.0 -0.08672 0.02119 0.01932 5

42275.3950 1 v -17753.0 -0.10268 0.00520 0.00332 5

42620.3830 2 v -16909.5 -0.10224 0.00331 -0.00013 6

42621.3960 1 v -16907.0 -0.11172 -0.00619 -0.00963 6

42633.4710 2 v -16877.5 -0.10209 0.00336 -0.00013 6

42990.5200 2 v -16004.5 -0.10600 -0.00324 -0.00801 7

43717.5060 1 pe -14227.0 -0.10918 -0.00557 -0.01147 8

43749.4180 1 pe -14149.0 -0.09882 0.00453 -0.00137 8

43756.3630 1 v -14132.0 -0.10674 -0.01065 -0.01655 9

43765.3750 1 v -14110.0 -0.09263 0.00337 -0.00253 9

44059.4290 1 v -13391.0 -0.10627 -0.01316 -0.01881 10

44815.4800 2 pg -11542.5 -0.08312 0.00174 -0.00171 11

45579.2837 1 peB,V -9675.0 -0.07822 -0.00290 -0.00270 12

45580.3070 2 peB,V -9672.5 -0.07735 -0.00204 -0.00183 12

45581.3296 1 peB,V -9670.0 -0.07727 -0.00197 -0.00176 12

45925.4350 2 v -8828.5 -0.14142 -0.07082 -0.06889 13

45932.4340 2 v -8811.5 -0.09534 -0.02483 -0.02287 13

45933.4590 1 v -8809.0 -0.09283 -0.02234 -0.02037 13

46143.4970 2 v -8295.5 -0.07392 -0.00642 -0.00349 14

46216.5100 1 v -8117.0 -0.06659 -0.00015 0.00311 13

46216.5120 1 v -8117.0 -0.06459 0.00185 0.00511 13

46217.5360 2 v -8114.5 -0.06308 0.00335 0.00661 13

46218.5490 1 v -8112.0 -0.07256 -0.00615 -0.00289 13

46228.5745 2 peB,V -8087.5 -0.06745 -0.00118 0.00212 15

46229.3929 2 peB,V -8085.5 -0.06704 -0.00079 0.00252 15

46230.4152 1 peB,V -8083.0 -0.06723 -0.00099 0.00232 15

46231.4379 2 peB,V -8080.5 -0.06702 -0.00079 0.00252 15

46233.4818 2 peB,V -8075.5 -0.06809 -0.00190 0.00142 15

46253.5130 2 v -8026.5 -0.07766 -0.01176 -0.00836 13

46259.4520 1 v -8012.0 -0.06910 -0.00328 0.00015 16

46270.4904 1 pg -7985.0 -0.07357 -0.00792 -0.00444 17

46286.4560 1 v -7946.0 -0.05879 0.00663 0.01017 13

47006.4933 2 peB,V -6185.5 -0.05780 -0.00354 0.00209 18

47062.3199 2 peV -6049.0 -0.05901 -0.00566 0.00005 18

47703.4324 2 peB,V -4481.5 -0.04666 -0.00422 0.00142 19

47717.3386 2 peB,V -4447.5 -0.04634 -0.00414 0.00148 19

47734.3105 1 peB,V -4406.0 -0.04773 -0.00584 -0.00024 19

48067.4454 2 peB,V,U -3591.5 -0.03947 -0.00361 0.00123 20

48072.3528 2 peB,V -3579.5 -0.04009 -0.00431 0.00051 19

48073.3726 1 peB,V -3577.0 -0.04273 -0.00697 -0.00215 19

48089.3261 1 peB,V -3538.0 -0.04001 -0.00455 0.00022 19

48090.3548 2 peB,V -3535.5 -0.03381 0.00164 0.00641 19

48091.3719 1 peB,V -3533.0 -0.03918 -0.00376 0.00101 19

48092.3958 2 peB,V -3530.5 -0.03777 -0.00236 0.00240 19

48108.5500 1 pe -3491.0 -0.03894 -0.00383 0.00088 21

48120.4115 1 peB,V,U -3462.0 -0.03827 -0.00338 0.00130 20

48439.4351 1 peB,V -2682.0 -0.03103 -0.00216 0.00136 19

48456.4089 2 pe V -2640.5 -0.03051 -0.00197 0.00148 19

48474.4055 2 pg -2596.5 -0.02975 -0.00156 0.00182 22

48500.3773 1 peB,V -2533.0 -0.02910 -0.00141 0.00186 23

48805.4973 1 peB,V -1787.0 -0.01971 0.00199 0.00386 23

 

 

HJD Min Type Method E Source (2400000+)

48829.4260 2 peB,V,U -1728.5 -0.01715 0.00407 0.00583 19

48835.3562 1 peB,V,U -1714.0 -0.01745 0.00365 0.00538 19

49151.3137 2 peB,V,U -941.5 -0.00879 0.00588 0.00603 19

49151.5181 1 peB,V,U -941.0 -0.00888 0.00578 0.00593 19

49515.3267 2 peB,V,U -51.5 -0.00164 0.00536 0.00368 19

49522.4858 1 peB,V,U -34.0 0.00004 0.00689 0.00518 19

49536.3916 1 peB,V,U 0.0 -0.00002 0.00653 0.00474 19

49556.4335 2 peV 49.0 0.00113 0.00723 0.00535 24

49556.4340 2 peB 49.0 0.00163 0.00773 0.00585 24

49590.3788 1 peB,V 132.0 -0.00013 0.00526 0.00321 25

49596.3117 2 peB,V 146.5 0.00229 0.00755 0.00547 25

49598.3573 2 peB,V 151.5 0.00291 0.00813 0.00604 25

 

Year Phase D₁ D₂ Ref.^a Covar.

1959 97% V 0.02 0.01 0.54 0.55 1

1983 100% V 0.00 0.06 0.62 0.57 2

1985 100% V -0.04 0.01 0.55 0.50 3

1989 99% V -0.01 0.04 0.56 0.52 4

1990 98% V 0.03 -0.01 0.55 0.59 4

1991 99% V -0.02 0.06 0.59 0.51 4

1992 91% V -0.03 -0.01 0.55 0.53 4

1993 99% V -0.01 -0.02 0.54 0.55 4

1994 99% V -0.03 0.00 0.56 0.53 4