### OBSDATE ###
20130422

### LOGDATE ###
130423

### OBSERVERS ###
MJI

### WEATHER ###
Clear

### LOCATION ###
Home

### PROGRAM ###
Fringes on 160m. Diameter of Beta Cen and Beta Cru. Orbital point for tau Sco.

### SIDEROSTATS ###
  n4    s4

### TARGETS ###
hr 4853 (Bet Cru)
hr 4656 (del Cru)
hr 4853
hr 5132 (eps Cen)
**
hr 5132 (realigned)
hr 5267 (Bet Cen, fringes at -180 to -160)
hr 5267 (Bet Cen, fringes at -140 to -150, i.e. second component, then jumpted to the 160 micron component)
hr 5267 (Bet Cen, Setas a 5 -2, to try and keep the -140 micron component, now at -125 microns. Even this proves not to be possible - the 160 micron component is stronger)
hr 5358 (v Cen, V=4.35, very strong fringes with 30 sec locks and S/N 5 times above threshold)
hr 5267
hr 5482 (V=5.36, limiting factor was S T/T lock, probably only 50% of the time locked - going fainter would need a brighter S beam or photon-counting mode)
hr 5267 (both fringe packets now visible in one frame)
hr 5132
hr 5267
hr 5358
***
hr 6143
hr 6165
hr 6070 (V=4.79, fringes not as clear as earlier on this magnitude - also lost STT for a while)
hr 6165
hr 6252 (lost LDC during acquisition, and even after a re-index, S appeared brighter than N. I could only assume that the wrong star was acquired - likely mu01 Sco in S, mu02 Sco in N)
***
hr 5132: Could not acquire in S4 due to pointing/indexing issues. Give up.






### QUALITY ###
Very good (several calibrated points)  

### PROBLEMS ###
S4 seemed to have a different autocol position to yesterday. Now 180.715, 359.603, which from memory moved +0.2 in azimuth. Seems to be a major indexing problem.

N4 image quality still wasn't fantastic, but the flux of 1.5e4 to 2e4 at gain 190 for bet Cru was higher than previous (and higher than S4 by a factor of 1.5 to 2). No focusing or alignment was attempted until eps Cen, between first and second runs. See below.

N4 Offsets: -82 34
S4 Offsets: -320 -42 (bet Cru, at transit)
S4 Offsets: -363 -42 (bet Cru, second obs)
S4 Offsets: -284 -20 (eps Cen)
S4 Offsets: -400 -5 (v Cen)
S4 Offsets: -640, -42 (eps Cen, second acquisition)
... which obviously means that S4 is losing incremental encoder ticks.

Fringe offset: -350 to -430 (bet Cru and Cals)
-200 to -120 (bet Cen and initial Cals)

Optimal focus for eps Cen (second try): 235000,80000. At this adjusted focus, the North image quality was certainly the best in my memory.