Lunar Occultation of 104 Tau on Oct-28th

[Tim Haymes]

I have received a request from Bob Argyle (researching double stars) to observe a lunar occultation of 104 Tau on October 28th at 02h.  (see table ).   This is Aitken 1934 (ADS 3701). A close double star unresolved by speckle interferometry 1983.93.

A planetary camera, video or a mobile phone recording at 25 to 30 fps (or faster ) through a telescope will be helpful in attempting to confirm a companion. The recording of the reappearance dark limb (RD) could be a step-wise egress which would then indicate the secondary star. A method used by lunar occultation observers. The star is magnitude 4.9

The occultation isn’t observable from S/SE UK (Greenwich), but a graze on the bight limb (or miss) is expected in this area. Observers north of Birmingham will see the reappearance on the dark limb with the star being further from the Southern cusp.

The Lunar Section will be please to receive reports of this occultation.

Reading and Greenwich – no occultation ( approximate UT )
Table:
Location        Ph    UT   Cusp Angle
Oxford           RB 0231  bright limb
Birmingham   RD 0237  CA 3 S
Manchester   RD 0241  CA 15S
Leeds            RD 0243  CA 17S
Carlisle         RD 0246  CA 20S
Edinburgh    RD 0248  CA 30S
Aberdeen     RD 0252  CA 35S

Tim Haymes
Lunar Section (Occultation group)

[Lars Lindhard]

I have mentioned this event in the danish astro forum.

Now they ask for an instruction  – how to do it.

Is there a manual or something similar somewhere?

Lars

[Tim Haymes]

Hello Lars,

Thanks for publicizing this occultation. The dark limb reappearance for an observer in Aalborg is 0304h 12s UT and the cusp angle in 29 S.   Someone with some experience in Lunar occultations who is able to use a planetary camera (or team up) would be equipped to record the star appearing. The observer would need a field of view of say 1/3 degree to be sure of including the limb where the star appears. I would suggest a frame rate of 25fps or 30fps. from 0303 to 0305 hrs. If this is successful  then we can do some photometry – i would need a copy of the AVI or SER file. 

There is only one previous recording of the star being occulted (by Brian Loader – NZ) and it was not double, or not time resolved. We seek further recordings. This event  is one of the last few opportunities, then the saros ends in 2019.  If you are Lunar observer (Imager?), perhaps your experience can help others observes to record the occultation.  I am too far South to attempt this.

Good luck and clear skies – Tim (Reading, UK)

[Tim Haymes]

The IOTA North America web site has many useful publications and links to occultation observing techniques. There may not be much info’ on the use of USB-CCD planetary cameras in these publications.  Only with Windows 8 and 10  does the timing facility of these systems become more reliable (another story).  Anyway we are not looking for exact UT for 104 Tau to help solve the double star question.  (in my view).  We will use a light curve measured from an AVI recording.

Visual impressions would also be nice too, if no video camera is available. All observations sent to the BAA Lunar Section will be acknowledged. 

http://www.asteroidoccultation.com/observations/NA/

[Lars Lindhard]

Hello Tim

Thank you. I will pass this info on and hope that someone will give it a try. If the weather permits….

[Lars Lindhard]

I watched the occultation of 104 Tau tonight in a 14″ SCT with af 8.8 mm eyepiece (323x).

Clear sky and 0˚ C. 

I observed both ingress and egress. 

The star reappeared instantaneous, there was no step-wise egress.

I believe other observers in Denmark had the same experience.

Lars

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