mu1 Sco (HD151890)
Aim of the campaign
This is a semi-detached system which despite, or perhaps because of, its brightness has been neglected by photometrists. The initial aim is to determine accurate Time of Minimum for several primary and secondary eclipses. We will repeat TOM measurements each season in order to accurately determine the period.
{tab Data}
| STAR | Max V Mag | RA 2000 | BRNO epoch (HJD) | BRNO period | Primary / secondary |
| mu.01 Sco | 2.94 | 16h51m52.2s | 2449534.1780 | 1.44627 | p |
| 2412374.4340 | 1.44627 | s | |||
| Min V Mag | DE 2000 | Krakow epoch (HJD) | Krakow period | ||
| 3.22 | -38°02′ 51″ |
Recent data: 2455729.99677 (0.00012) TOM for primary eclipse (M. Blackford)
{tab Light Curve}
From Shobbrook, R.R., The Journal of Astronomical Data 10, 1 (2004)
{tab Observing Notes}
No bright field stars close enough to interfere with measurements. Target and comparison 2 are very bright therefore the lens will have to be stopped down to allow exposures of 10 seconds or longer.
{tab Finder Chart}
The field of mu1 Sco is shown in the plot below.
{Tab Comparison Star Data}
Please use the four comparison stars labled on the chart and catalogue values listed below.
| Comp Star | Name | RA (J2000) | DEC (J2000) | V | B-V | V-Rc |
| 1 | HD150608 | 16 43 47.60 | -38 09 22.5 | 6.045 | -0.061 | -0.045 |
| 2 | HD151985 | 16 52 20.13 | -38 01 03.4 | 3.542 | -0.198 | -0.136 |
| 3 | HD153072 | 16 58 52.25 | -37 37 13.5 | 6.048 | 0.183 | -0.042 |
| 4 | HD150742 | 16 44 42.60 | -40 50 42.6 | 5.628 | -0.099 | -0.051 |
{tab Preliminary Results}
The plot below shows a primary minimum observed by Mark Blackford at HJD ~2455730.00028 which is roughly 8 minutes earlier than the BRNO prediction. There is quite a bit of scatter in the measurements and more data is required before and after the minimum.
{/tabs}