Dauban V243


nameDauban V243
constellationVul
J2000.020 23 19.16 +21 50 52.4
other names2MASS J20231916+2150524
typeEA
mag range12.7 - 13.8 CR
period (days)--
epoch--
colorJ-K = 0.38
remarks--
links--
discovery26/12/2012
DSS2-R
DSS2-IR


Confirmation of variability


Additional observations have been made with a 200mm reflector. The data confirms the occurrence of eclipses.



Photometric data


We provide magnitude data in the tables below. All the images have been carefully checked prior to photometry based on the following criteria: (1) normal value of magnitude zero point, (2) sky background is uniform across the image, (3) air mass < 2.5, (4) stars are sharp and not elongated in the E-W direction, (5) for the 80mm refractor only: accuracy of astrometric reduction is better than 0.5 pixel.

For the 80mm refractor, three 10 sec exposures are taken. The magnitudes are measured on the median of the three images.

For the 200mm reflector, the exposure and number of images taken is changing. The magnitudes values are measured on each individual image. For each night, a median is taken over several consecutive measurements to obtain the final magnitudes reported in the table. The number of values used for the median is indicated in the table third column. If it is greater than 3 the data is very reliable. If only 1 image was used, the data is probably fine but we cannot guarantee it does not contain an error.

Dauban Survey (80mm F/7.5 refractor)
Julian dateCR magnitude
2456190.36916912.764
2456195.39663412.759
2456202.37436112.784
2456205.35415412.742
2456206.34617612.705
2456210.32335113.821
2456213.30966712.818
2456225.30385412.809
2456230.31821912.836
2456234.30340312.818
2456238.28877712.802
2456243.32803912.753
2456250.28105712.795
2456261.28234212.780
2456271.27576013.846
2456288.28124112.723
2456401.61903812.831
2456461.43142412.753
2456474.57519712.748
2456485.48149212.863
2456502.40900612.750
2456516.59111012.867
2456523.39730512.747
2456540.44597712.813
2456549.54284812.912
2456558.42603112.809
2456566.41537613.498
LX200 (200mm F/10 reflector)
Julian dateCR magnitudenumber of images
used for photometry
2456504.37932112.7653
2456504.42289912.7833
2456504.46672712.8183
2456504.51147912.8463
2456504.55502112.8293
2456505.41343912.7653
2456505.43381612.7633
2456505.45367012.7603
2456505.47263812.7663
2456506.34640312.7223
2456506.36493812.7323
2456506.38400312.7433
2456506.40418012.7583
2456506.38782312.7433
2456507.36539412.7581
2456507.36556112.7621
2456507.36572512.7111
2456508.36281212.7523
2456508.38109012.7183
2456508.39920912.6543
2456508.41787012.7363
2456508.39949312.7193
2456509.36915312.7293
2456509.38620012.6503
2456509.40312212.7483
2456510.34811612.7461
2456510.34827612.7121
2456510.34843212.7921
2456518.35202012.75025
2456518.36400512.74725
2456518.37597912.74925
2456518.38823212.76025
2456518.40040312.74625
2456518.41239612.74625
2456518.42507112.75825
2456518.45089612.75725
2456518.48203512.74011
2456522.42073412.77725
2456522.46836312.80825
2456522.50367912.83725
2456522.58815112.8346
2456551.30410212.71114
2456556.29795012.81215
2456558.27435112.74910
2456559.28081612.73715
2456560.28343212.71715
2456561.29597412.74715
2456563.31623512.75715
2456565.31402712.80215
2456566.29157912.75315
2456571.28887812.75315
2456573.27510714.21215

Period search


Eclipses have been observed at these dates:

Eclipse julian dates
2456210.323351
2456271.275760
2456566.415376
2456573.275107


A period search gives the following phase residual:



The period search is quite difficult in this case. Possible periods are:

Possible periods
3.3922 days
2.2537 days
2.3420 days
6.718 days
6.853 days