The list shows occultations of possible double stars during February. Although the main emphasis remains on stars with separations < 2", now that the more detailed lunar limb profile from LOLA is available, some wider pairs are included. Doubles predicted to be occulted by the Moon during February 2018 and visible from parts of Australia or New Zealand are included. The listing is a very abbreviated version of predictions produced by Occult plus an indication of the region of visibility. Observers need to generate their own precise predictions using Occult.

The list below is generated by OCCULT for a 25cm telescope. Some of the events could be beyond the reach of smaller telescopes. Observations of all pairs in the list are highly desirable. Those showing an OCc number have been reported as non-instantaneous at a lunar occultation. Confirmation or otherwise of any double nature is wanted.

*** Kepler stars: the nights on which they are occulted are indicated. Individual Keplers are only shown if they are also a known or possible double. Light curve of occultations of all Kepler stars are desired.

Please send reports of all observations of these stars to Brian Loader at brian.loader@slingshot.co.nz, including any made in earlier months and not so far reported. And of course if you observe a stepped event for a star, which is not a known double, please report this. More details about reporting follow the predictions.

ARCHIVING OCCULTATION LIGHT CURVES

For ALL lunar occultations: single, double and Kepler K2 stars a csv file should be prepared for archiving. This can be done through the OBSERVATIONS EDITOR of OCCULT.

It will be necessary to generate a light curve using LIMOVIE and save or copy its csv file. You will also need to note the time, hh:mm:ss.sss of one frame and the corresponding frame number.

Then in the Observations Editor select the entry for the star and use the menu bar option to create a Light Curve Report. Follow the instructions on the new screen which appears. There is a help file. It is suggested that light curve reports be emailed in batches rather than singly. They are sent directly to Dave Herald from the program.

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 d P    Star  Mag    %         Double details        WDS or   Area of
Feb      No    v    ill      magnitudes sepn    PA?  OCC #    Visibility
 2 r   *** Kepler Stars occulted, light curves are desired    RBTSCM,AkWChI
 2 R    1596  7.2   94- : AB  7.2 12.0  1.6"  114.5  A  2774  BTSCM
   ***  1596 is in the Kepler2 program {ID = 248769093}
 3 r   *** Kepler Stars occulted, light curves are desired    RBTSC,AkWChI
 4 r   *** Kepler Stars occulted, light curves are desired    RBTSCM,AkWChI
 5 r   *** Kepler Stars occulted, light curves are desired    R
 6 r  139898  7.6   60- : AB  7.5  7.5  6.0"  175.1  STF1833  BTSCM,AkWChI
      139898:  B star is R 2059 
 7 r X 39132# 9.5   49- : **  9.6 11.8  0.07"  93.0  OCc1843  RBTSCM
 8 R    2284  5.0v  41- : **  5.5  5.5  0.05" 350.0  OCc1486  ,I
10 r X 42586 10.1   23- : **  9.5 10.8  0.07" 101.0  OCc1747  ,ChI
11 r  161607#10.0   14- : AB 10.1 10.6  2.2"  281.1  B  1887  RBTSCM
      161607:  B star is X158261
11 r  161648  8.9   14- : AB  8.9 11.8  9.4"  325.3  ARA 756  RM
12 r   *** Kepler Stars occulted, light curves are desired    RM,AkWCh
13 r  163386  9.5    4- : AB  9.7 12.6  0.60" 279.2  RST3252  BTSCM

18 d  146972  9.4    6+ : **  9.6  9.6  0.10"  90.0  OCc  95  ,Ak
   *** 146972 is in the Kepler2 program {ID = 246280444}
19 d   *** Kepler Stars occulted, light curves are desired    RB
20 d   *** Kepler Stars occulted, light curves are desired    R,AkWCh
22 d   93411  8.7   40+ : **  9.3  9.3  0.10"   9.0  OCc 626  RBTSCM
23 d   *** Kepler Stars occulted, light curves are desired    R
23 d   93860  8.5   51+ : **  8.9 11.0  0.06" 244.0  OCc 938  M
23 D     648* 3.8s  52+ : Aab 3.9  9.5  0.7"    9.6  CHR 262  SCM
24 d   *** Kepler Stars occulted, light curves are desired    RBTSC,Ak
24 d X 73360  9.0   62+ : AB  9.1  9.6  1.7"  252.6  STF 665  TSCM,I
     X 73360:  B star is X  6728, in the Kepler 2 program
25 d     957  8.9   73+ : AB  9.2 10.3  0.40" 105.0  TDS3701  RBTSCM,AkWChI
   ***   957 is in the Kepler2 program {ID = 202059336}
25 d   78232  9.3   73+ : AB  9.7 10.5  0.41" 265.9  HU  453  RB
   *** 78232 is in the Kepler2 program {ID = 202059343}
25 d   *** Kepler Stars occulted, light curves are desired    R
26 d   79282  8.7   83+ : AB  8.7 12.2  0.13" 166.4  HDS1019  ,ChI
26 d   79291  8.6   83+ : **  9.5  9.5  0.05" 350.0  OCc1354  BTSCM,AkWChI
26 D    1123  7.3   84+ : AB  7.3  8.1  6.8"   46.0  STF1083  RBTSCM,AkI
        1123:  B star is S 79376
26 D    1127# 5.9   84+ : AB  5.9       0.03" 292.8  CHR  26° RBTSCM,Ak
27 d   *** Kepler Stars occulted, light curves are desired    RBTSCM,AkWChI
28 D    1387  7.0   96+ : **  7.6  7.6  0.10"  90.0  OCc1402  ,AkWCh


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Visibility codes:
Australia: R Rockhampton, B Brisbane, T Tamworth, S Sydney, C Canberra, M Melbourne  

NZ (following a ,) Ak Auckland, W Wellington, Ch Christchurch, I Invercargill.
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Stars with previous occultation observations: 

#: Observations indicating double - these need further checking
*: Observations not showing double - need confirmation
!: Recent video discoveries - confirmation needed.
?: Uncertain double observation, confirmation or otherwise needed

A WDS number followed by a ° sign indicates the double has a known orbit.

==================================================================

Reporting Your Observations

The most convenient way of reporting is to use Dave Herald's OCCULT which has a Double Star report option in the Observations editor. Before using it, generate a light curve with Limovie and copy to the clip board. Your graph will be attached to the email which you can then send to brian.loader@slingshot.co.nz.

Otherwise in reporting please include your name and positional data as for other occultations reports, also your telescope type and method of observing and timekeeping.

For each event give the star name and the times of each step of the event with the corresponding accuracy. The limb PA, Rv and Cct of the event would also be useful.

In addition to measures of the PA and separation of binary stars, there is also a need for an estimate of the magnitude difference. An estimate of this can be made from the step sizes shown by Limovie data. So if possible a determination should be made of the size of each step together with an estimate of accuracy.

Please also report cases where a double event is predicted but none detected. These are especially likely with stars shown with an OCc designation

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