This week we look at the object TX Ori in the Sigma-Ori HOYS target field. We have studied this object in detail in a recent paper (Froebrich D., Eislöffel J., Stecklum B., Herbert C., Hambsch F.-J., 2022, A survey for variable young stars with small telescopes: V – Analysis of TXOri, V505Ori, and V510Ori, the HST ULLYSES targets in the σ Ori cluster, MNRAS, 510, 2883). We also looked at the light curve in previous posts (in weeks 141, and 192).

In the plot above we show the first data of the source, which we have processed into the newly opened database. Note that for now, the light curve plotting on the website will only show data that has been entered since 29.03.2023. We are working in the background to restore all the photometry into the live database. This will be accompanied with major changes to the background organisational structure of the tables, a cross-match to Gaia positions, and thus a much improved speed when searching for and returning light curves.

There is a special ‘feature’ in this light curve, which has nothing to do with the star itself. But if you look carefully at the time axis in the light curve plot, you can see that the Julian Date (JD) changed to the next full 10000 days. This happened on February 24th at noon UT and is quite a rare event, happening only every ~27yr. The next time JD will be changing to the next 10000 will be Noon on Tuesday July 12, in 2050.