[pasmembers] Re: Mercury Transit

  • From: Leah S <lphxaz@xxxxxxxxx>
  • To: pasmembers@xxxxxxxxxxxxx
  • Date: Mon, 2 May 2016 12:32:02 -0700

actually if you look at the AL rules, they have an option where the other photographer does not need to be a member of AL, as long as the AL member does the calculations. see #2 and 3:

1. You can partner with another member of the Astronomical League who
   is located at a distance from your observing location.
2. You can observe from your location and get a second observation of
   the transit from a remote observatory location from the Internet.
3. Or, if you are not able to see the transit on May 9th, you can use
   observations from two remote observatory locations from the
   Internet. Observations must be done through imaging.

does anyone want to try this? even if Alex and Bob are partnering, we can always compare their photos with those of a third photographer; or maybe someone else wants to take up the challenge.

also, regardless of whether it qualifies you for an award from AL, why not do this just for the fun and challenge, to see what result it gives, with the opportunity to compare two very distant simultaneous photos?

I have heard back from an Israeli astronomer who is planning to photograph the transit. he wrote that he can put his telescope on a timer for the purpose of calculating the AU. he suggests that we synchronize our clocks by UTC and then take pictures on the hour and at 15-min intervals. but - sunset here is a little after 1600 UT. would someone be able to take picture starting from 1500 or even 1400 UT? this would be 7 or 8 am in Phoenix.

On 5/2/2016 11:14 AM, Alex Vrenios wrote:

Hi Leah,

Wow - that certainly qualifies for the “distant partner” in the AL’s program requirements!

They would have to be a member of the Astronomical League, however, and I’ll bet you won’t find anyone (other than yourself that is) in that capacity. I’m attaching a copy of the presentation slides. I assume you won’t be flying half way around the world to see my talk :)

I’m partnering with Bob Ewing. We will be taking three images, one at 1600, 1700 and 1800 UTC. He is still officially a member of the AL as well as PAS, but he got a teaching job back in Portland Oregon, where he’s from originally. So I’m covered, but thanks for the offer.

Hope you’re doing well,

Alex




Of course, this doesn’t have the actual images yet. I’ll plug them in where it says “actual photos follow.”

On May 2, 2016, at 10:18 AM, Leah S <lphxaz@xxxxxxxxx <mailto:lphxaz@xxxxxxxxx>> wrote:

I don't know what is the big deal. it is easy to find out the distance to the sun! just look it up on wikipedia! :)

of course if you want to measure it yourself, just point a laser at the sun and time how long it takes for the light to come back. probably you would want to do this at night when it's dark... :D

ok, all kidding aside... I have spoken with some people in Israel and I might be able to find you a partner here on the other side of the globe. the transit will be visible here from the beginning of the transit till sunset, which is around 7 pm local time, i.e. 9 am in Phoenix.

I'll let you know if I find someone to participate, if you are interested.

On 4/12/2016 5:11 PM, Alex Vrenios wrote:
You don’t need to see Mercury at any of the four contact points. You need to have someone at a distant location take a photo of Mercury at the exact same time that you do. Both photos must contain the full Sun for alignment. If you have more than one simultaneous photo, so much the better, but one is all you need for our level of accuracy.

Make two prints and superimpose them. Measure the diameter of the printed solar disc, then measure the distance between the two Mercury-image dots. Finally, you need the distance between you and your cohort. Plug in these values and calculate the value of 1 AU.

I’ll be presenting all this in detail at the May 5th meeting.

Alex
On Apr 12, 2016, at 3:26 PM, Peter Turner <peteturner@xxxxxxxxxxx> wrote:

I guess I’m confused about how we can do the measurement. It’s my understanding that we need to be able to see Mercury as it touches the eastern limb of the sun and as it touches the western limb. Since the transit starts prior to the sun rising for viewers in the west, how do we do this?
/Pete Turner/
*From:*pasmembers-bounce@xxxxxxxxxxxxx[mailto:pasmembers-bounce@xxxxxxxxxxxxx]*On Behalf Of*Alex Vrenios
*Sent:*Monday, April 11, 2016 9:29 PM
*To:*pasmembers@xxxxxxxxxxxxx
*Subject:*[pasmembers] Re: Mercury Transit
Here’s my thinking on the matter. If we are both watching the Sun rise, I imagine us both standing on the “side” of a sphere, looking east, toward the Sun above our horizon.
With that image in mind, our difference in latitude is what would influence the offset between our two projections of Mercury’s disc onto that of the Sun. Our difference in longitude is trivial when compared to the distance between us and the Sun.
Alex
On Apr 11, 2016, at 9:12 PM, Robert Ewing <rrewing9@xxxxxxxxx <mailto:rrewing9@xxxxxxxxx>> wrote:
Hi Alex...and Ted and all.....nicely done....
I was wondering about the difference in longitude between us being a factor. But if we both (and others too) use horizontal lines across the solar disc and
measure parallax angle from those lines (across opposed to using specific points) we should be ok. Boy, do we have to be precise!! The parallax will be 1/3 the diameter of Mercury's disc!! Ha!
I will see if I can get someone in Bend, Oregon to join us because it will almost certainly be clear there. Very dry. Central Oregon Community College is there. Also Pine Mt. Observatory (where I used to do education/public outreach).
Cheers everyone!
Bob E
On Apr 11, 2016 5:06 PM, "Alex Vrenios" <axv@xxxxxxx> wrote:
One thing, if I’m reading the requirements correctly, is that anyone can pair up with anyone else. That is, if Ted and Bob get images at exactly 9am, 10am and 11am Phoenix time (1800, 1700 and 1600Z), anyone else in the club can use their images same-time to perform the measurements and calculations. Bob and Ted can only pair up with one of us, but I see no prohibition against anyone or everyone using these images to compare with their own.
Bob and I have a PowerPoint slide set that describes the details. I plan to use them at the May 5th meeting to show what this is all about. I will be happy to send a PDF to anyone who may not be able to attend the May meeting.
Alex
P.S. There are options in case the sky is cloudy at one or both locations, allowing an AL member to use imaging over the Internet at one or even two web locations to gather the data. I asked if a screen shot of a live stream was okay. I also pointed out that the only “remote imaging” site I could find, atiTelescope.net <http://itelescope.net/>, told me they do not offer a solar imaging service at this time. The AL coordinator said he would contact some others and let me know how they plan to change these options.
P.P.S. The AL’s Transit of Venus (in 2012) did NOT require two sets of images. You only had to make a sketch and then go to a NASA site to do three “activities,” one of which was to download their images and plug in your measurements to get the calculated value of 1 AU.
On Apr 11, 2016, at 4:01 PM, Ted Blank <tedblank@xxxxxxxxx> wrote:

I will be on the East coast for the Mercury transit and would love to try this with club members back here in Phoenix. It's about time we knew how far away the sun was! 🌝

Best regards,
Ted Blank
(603) 817 9814 <tel:%28603%29%20817%209814>(cell)
Sent from my iPhone


On Apr 11, 2016, at 2:43 PM, Terri <starstuff@xxxxxxxxx> wrote:

Alex,
the May 5 meeting would work good for a discussion about this project, if you want to prep something about it. Dan doesn't usually do too long of a presenation, so we should have time after his talk to discuss the Mercury transit
Sam, is this ok with you and should we put it on the agenda?
I want to hear about it, even if I'm not planning to do it. Sounds intriguing.
Terri
On Sun, Apr 3, 2016 at 12:53 PM, Alex Vrenios <axv@xxxxxxx> wrote:

The Astronomical League is offering an award (pin and certificate) for meeting the requirements as stated on their websitehttp://astroleague.org. Scroll down to “Mercury Transit Special Award is now here” and click on the word “here” at the end of that paragraph. This page has all the requirements you must meet in order to receive the award. All members of PAS are automatically PAS club affiliates of the AL so your first requirement is already met.

The next set of requirements are not for the faint at heart. They involve the cooperation of two observers at some distance apart (PVCC to BMC should be enough) and a lot of trigonometry. You and your partner will be using the separate observations to calculate “1 AU” the distance from the Earth to the Sun.

I need to look at the details more carefully first, but I’d like to propose a short talk about this at an upcoming meeting if there is any interest.

Alex



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