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Delta Orionis Campaign

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Delta Orionis Campaign

There is a Campaign to observe deta Orionis (Mintaka) the right most star in Orion's belt. The Campaign begins next week on 17 December 2012. Multiple observations per night are requested. Because the Star is so bright (V = 2.41), CCD photometry is very difficult. Even single channel photon counting would be near saturation. The project is ideal for single Channel SSP-3 BVRI photometry, however. DSLR V band is also a possiblity. Anyone interested in helping with this project pease comntact me directly at More information about the Campaign can be seen at


Jeff (187283)
Hopkins Phoenix Observatory

ldj's picture
Its unforunately that the

Its unforunately that the pros give the amateurs but a few days notice of this. Not very realistic given that usual CCD techniques won't work and adjustments to filters (NDs, etc) and processes would have to be made. Oh well, it would have been a compaign to take part in, but not on 3 days notice.

Dave (LDJ)

Delta Orionis Campaign


Hi Dave,

I apologize for not posting this sooner. The Campaign has been underway for a couple of months. Because normal CCD photomety will be very difficult, I was hoping hte AAVSOnet BrightStar monitor could help. As it turns out it does not look like it can. The are a couple of people who have expressed interest and at least one will be using an SSP-3 which is ideal for this Campaign. Also anyone doing high-resolution spectroscopy will find the Campaign easy. SInce it will be going on for several weeks any observations should prve valuable. So far very few observers have committed to it.


ldj's picture
Hi Jeff, The "target" for

Hi Jeff,

The "target" for my comment wasn't your message, but rather the Alert Notice that went out earlier in the day.

I did a bit of searching for ND filters and did not come up with much. Does anyone know if something like 1% (or less) neutral density filters that are fairly flat across the optical band are readily available?

Good luck with the program.

--- Dave

HQA's picture
neutral density filters

Edmund Scientific is a good choice for neutral density filters:

the reflective type will be the most wavelength-uniform.  You can also often use a photographic neutral density filter, and mount it offset in a mirror cover.

The bigger problem with bright stars is finding suitable comparison stars.  If the comparison is not in the same field of view, then you are restricted to only photometric nights for your observing.  For del Ori, we can see a few faint stars in the BSM 2x1.5 degree field of view; with stacking to increase the dynamic range, you can possibly be able to do on-chip comparison star differential photometry.  However, with a much smaller field of view, you may have difficulty in doing this.


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