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Request for a Scientific Observation, Mercury transit November 11

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#1 Aquarellia

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Posted 13 October 2019 - 11:12 AM

As you probably know, some of us must be able to observe (weather permitting) the next transit of Mercury on November 11, 2019.
In Europe, we are able to see the first contacts and from America, just the last ones.
One of my friends: Jean Bourgeois ask to try to determine the depth of the solar chromosphere. I do not know if you know about it, but we do not yet know exactly how big that chromosphere is.
The next transit of Mercury allowed observers to time the beginning and / or end of this event in two different wavelengths: in green light, corresponding to the photosphere, and in Halpha, corresponding to the chromosphere. The difference between these two times would give an estimate of the thickness of the chromosphere at the solar latitudes concerned. We do not take into account chromospheric spikes, but only the chromospheric layer, which in fact corresponds to the difference of the sun's radius in these two wavelengths.
This type of observation is rarely achieved. The literature mentions only three observations, one by Russ Sampson in 1994 (Sky & Telescope, November 1994), the other by Jean Bourgeois himself in 1996 (IOTA / ES, symposium of 1997) and the last of April 2003 via IOTA and the association of solar observers also by Jean Bourgeois. Unfortunately, almost all the efforts to time the events in Halpha failed, due to clouds, low-precision images or technical problems.
We have now a good program to reduce the observations, this was done by another of our friends, Jean Meeus.
So, if you want to be part of this new challenge, do not hesitate to contact me via this CN post or directly via Private Message.

 

I attach here under the paper that Jean Bourgeois wrote in 2003, with more explanations on this phenomenon and on the way to organize the observation.

 

Attached File  Mercury-Transit.pdf   368.33KB   88 downloads

 

Clear sky to you all

 

Michel


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#2 Greyhaven

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Posted 13 October 2019 - 12:21 PM

Michel

Thanks for keeping the upcoming transit talked about. I live on the East Coast in the U.S.. Our local sunrise occurs at 6:30 AM. A full hour before the transit begins so 1st and 2nd contacts may well be manageable as well. I show the transit local times as 7:30 AM to 1:00 PM  so unless your local eastern horizon is obstructed many in the  eastern U.S. and eastern Canada do have good seats for the event. Go forth and spread the word to the faithful.

Grey


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#3 TOMDEY

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Posted 13 October 2019 - 12:34 PM

1.2 second differential... Hmmm... that should be doable. Two video cams with synchronized clocking stamps. Interesting!

 

Seems a total Solar Eclipse would provide the same opportunity... like high-speed radiometers at diamond ring... one Ha and the other green The rise/fall curves could be nicely convolved/autocorreletad (in the time domain) to accurately determine the time differential... and infer the "depth of the chromosphere"? I assume that has already been done, too?  Tom



#4 nicoledoula

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Posted 13 October 2019 - 01:01 PM

I bet the flat earthers who will also be observing, filming and correlating data will come to different conclusions about the size of the Sun and it's distance from Earth....


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#5 wargrafix

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Posted 13 October 2019 - 01:05 PM

i only have white light with my 9.25.

 

i wlil have, weather permitting, a view of the entire event. will this be of any use?



#6 dermarkus

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Posted 13 October 2019 - 01:45 PM

Michel, All,

It is definitely doable. It did exactly that during the May 9,2016 transit. My wife and I observed the transit visually. She was doing the whitelight and I was doing th h-alpha. We recorded the contact times on a voice recorder together with a time signal so we were able to calculate the contact time differences and finally and estimation of the thickness of the chromosphere.
Our results were published in the VdS journal a publication of the German amateur astronomy association (Vereinigung der Sternfreunde e.V.) which is online available for members. If you are interested I can send you a copy of it in a private message.

Thanks and good luck for the project
Markus
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#7 Aquarellia

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Posted 13 October 2019 - 02:32 PM

Michel

Thanks for keeping the upcoming transit talked about. I live on the East Coast in the U.S.. Our local sunrise occurs at 6:30 AM. A full hour before the transit begins so 1st and 2nd contacts may well be manageable as well. I show the transit local times as 7:30 AM to 1:00 PM  so unless your local eastern horizon is obstructed many in the  eastern U.S. and eastern Canada do have good seats for the event. Go forth and spread the word to the faithful.

Grey

Sure, near the north american East coast it is the better place for this show.  You'r a lucky man!

 

1.2 second differential... Hmmm... that should be doable. Two video cams with synchronized clocking stamps. Interesting!

 

Seems a total Solar Eclipse would provide the same opportunity... like high-speed radiometers at diamond ring... one Ha and the other green The rise/fall curves could be nicely convolved/autocorreletad (in the time domain) to accurately determine the time differential... and infer the "depth of the chromosphere"? I assume that has already been done, too?  Tom

Hi Tom, 1.2 second was for the rapid moon mouvement, for Mercury we are speaking about 25 to 35 seconds between the two wavelenght colors, much more easy, same for a single observer

 

i only have white light with my 9.25.

 

i wlil have, weather permitting, a view of the entire event. will this be of any use?

Idealy if you can have a contact with someone with a PST or any Ha Lunt, that could be usefull, the only interest about this manip is to observe the 2 colors simultaneously to detect the difference.

 

Michel, All,

It is definitely doable. It did exactly that during the May 9,2016 transit. My wife and I observed the transit visually. She was doing the whitelight and I was doing th h-alpha. We recorded the contact times on a voice recorder together with a time signal so we were able to calculate the contact time differences and finally and estimation of the thickness of the chromosphere.
Our results were published in the VdS journal a publication of the German amateur astronomy association (Vereinigung der Sternfreunde e.V.) which is online available for members. If you are interested I can send you a copy of it in a private message.

Thanks and good luck for the project
Markus

Markus, you make my day, in 2016 I had programmed the same type of experience with my wife and a chronometer, but the clouds were very there!

I send a PM to you.

 

Michel


Edited by Aquarellia, 13 October 2019 - 10:36 PM.


#8 Greyhaven

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Posted 13 October 2019 - 03:16 PM

Michel

"Sure, near the north american East coast it is the better place for this show.  You'r a lucky man!"

Yes me and quite a few million others in the colonies will have the opportunity (most won't) it's hard to know what's going on around you if you ignore science and live with your head in the sand. wink.gif

Grey


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#9 Aquarellia

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Posted 13 October 2019 - 10:53 PM

Hi we receive some interesting  questions in PM, all relared with the observation organization.

 

We have two problems, the  first one is because of the apparent size of the Mercury disk we have to reach a decent magnification. and the second problem, the wavelenght of the white light change with the type of filter used, it's not integrated light as without any filter ofcourse.

 

You have two solution:
1- The best observation coud be to use two videos with time inclusion, often observers are using GPS encapsulation of the time value directly on the image, exactly as when we record a star occultation by an asteroid or by the Moon.
1.1- so two videos, one in halpha and another one in white light but with a special filter centered on 546.1 nm wavelenght (green)
1.2- because of the "long" time between contacts a single camera could be used but during the half of this minute you must change from halpha to WL.  Some training is useful here.
2- The second solution is to record this time difference visualy with two different observers or two materials using the eye and a chronometer mesuring the difference between the two Top's.

This case is not so precise than the first one but need less material, the only real issue cane from the wavelenght of the white light filter.  I come back later for this point.

For the rest we need your precise position on earth, latitude longitude altitude, the time difference with the contact number (1,2,3 or 4) and the material used.

Hope this helps.
Michel


Edited by Aquarellia, 13 October 2019 - 11:05 PM.


#10 HxPI

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Posted 16 October 2019 - 05:54 AM

Hi we receive some interesting  questions in PM, all relared with the observation organization.

 

We have two problems, the  first one is because of the apparent size of the Mercury disk we have to reach a decent magnification. and the second problem, the wavelenght of the white light change with the type of filter used, it's not integrated light as without any filter ofcourse.

 

You have two solution:
1- The best observation coud be to use two videos with time inclusion, often observers are using GPS encapsulation of the time value directly on the image, exactly as when we record a star occultation by an asteroid or by the Moon.
1.1- so two videos, one in halpha and another one in white light but with a special filter centered on 546.1 nm wavelenght (green)
1.2- because of the "long" time between contacts a single camera could be used but during the half of this minute you must change from halpha to WL.  Some training is useful here.
2- The second solution is to record this time difference visualy with two different observers or two materials using the eye and a chronometer mesuring the difference between the two Top's.

This case is not so precise than the first one but need less material, the only real issue cane from the wavelenght of the white light filter.  I come back later for this point.

For the rest we need your precise position on earth, latitude longitude altitude, the time difference with the contact number (1,2,3 or 4) and the material used.

Hope this helps.
Michel

Would the Baader Solar Continuum Filter work for white light?


Edited by HxPI, 16 October 2019 - 05:54 AM.


#11 Aquarellia

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Posted 16 October 2019 - 06:19 AM

Would the Baader Solar Continuum Filter work for white light?

Visualy yes, no problem, for photo or video the use of a green filter as described in the PDF is better.

Michel



#12 TrackballJerry

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Posted 13 November 2019 - 02:14 AM

A friend and I inadvertently carried out this observation without realizing you had asked for data. We timed a 30 second difference between Mercury's last contact with a white-light filter (Baader Astrosolar film) and an H-alpha scope (Lunt 60mm). This is accurate to about plus or minus 2 seconds.

 

Location: N 43° 52.202', W122° 47.314', Elevation 1325 feet.

 

The only reason we got this data was because I was watching through the white-light scope and marked the time when the transit was completely over, at which point my friend who was watching through the H-alpha scope said, "I can still see it." So we timed his observation and last contact came exactly 30 seconds later for him. I was using a watch with sweep second hand, though, so I figure I could have been off by a second one way or the other for each observation.

 

Also the white light scope was using a magnification of 71x while the H-alpha was using 31x, so that could affect our perception of last contact.

 

Still, a little math gives us 1,300 miles for the depth of the chromosphere, which matches NASA's figure here [https://www.nasa.gov...a/layerzoo.html] pretty well.

 

Hope this data is useful!

 

-Jerry Oltion



#13 Aquarellia

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Posted 19 November 2019 - 10:24 AM

A friend and I inadvertently carried out this observation without realizing you had asked for data. We timed a 30 second difference between Mercury's last contact with a white-light filter (Baader Astrosolar film) and an H-alpha scope (Lunt 60mm). This is accurate to about plus or minus 2 seconds.

 

Location: N 43° 52.202', W122° 47.314', Elevation 1325 feet.

 

The only reason we got this data was because I was watching through the white-light scope and marked the time when the transit was completely over, at which point my friend who was watching through the H-alpha scope said, "I can still see it." So we timed his observation and last contact came exactly 30 seconds later for him. I was using a watch with sweep second hand, though, so I figure I could have been off by a second one way or the other for each observation.

 

Also the white light scope was using a magnification of 71x while the H-alpha was using 31x, so that could affect our perception of last contact.

 

Still, a little math gives us 1,300 miles for the depth of the chromosphere, which matches NASA's figure here [https://www.nasa.gov...a/layerzoo.html] pretty well.

 

Hope this data is useful!

 

-Jerry Oltion

Hi Jerry

 

I send your data to the responsible, mlaybe without any contact time this could be usefull, I don't know ?

I will let you know if yes!

Michel




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