Mercury sodium tail
Moderator: Montana
- KMH
- Almost There...
- Posts: 1044
- Joined: Sat Feb 22, 2014 4:45 pm
- Has thanked: 657 times
- Been thanked: 760 times
Mercury sodium tail
You may have read about the recent visibility of Mercury's sodium tail. A number of elements are sputtered off the surface of Mercury by the combination of solar wind and micrometeorites, forming a very low density (non-collisional) atmosphere of sorts. Some of this material is blown away from Mercury by radiation pressure, similar to what happens with a comet. One of the primary components is atomic sodium, which exhibits very strong resonant scattering at 589 nm. However, the sun has a strong Fraunhofer absorption feature at 589 nm due to sodium in the outer atmosphere, so much of the time the Mercury's sodium tail is not very bright. But +/- about 16 days from perihelion Mercury has it's maximum radial velocity with respect to the sun (its orbit is highly eccentric). The resulting Doppler shift increases the wavelength of the photons necessary for sodium scattering to the wings of the absorption feature, so that the intensity of (Doppler shifted) 589 nm radiation at Mercury increases by about 10x relative to perihelion.
We saw some examples of amateur imaging of the tail using narrow-band filters and decided to give it a try - with success! Still working on processing but here is an example from 5/12/21.
80 mm f/6 refractor
Canon 6D DSLR
Edmund optics 589 nm filter with 10 nm bandpass.
Stacked five 30 second exposures.
There is significant vignetting because the filter is only 1" diameter. Also, it is not an image quality filter, which doesn't help! But we were excited to see anything.
NOTE - the tail was predicted in the 1980s but not observed until 2001.
Kevin
We saw some examples of amateur imaging of the tail using narrow-band filters and decided to give it a try - with success! Still working on processing but here is an example from 5/12/21.
80 mm f/6 refractor
Canon 6D DSLR
Edmund optics 589 nm filter with 10 nm bandpass.
Stacked five 30 second exposures.
There is significant vignetting because the filter is only 1" diameter. Also, it is not an image quality filter, which doesn't help! But we were excited to see anything.
NOTE - the tail was predicted in the 1980s but not observed until 2001.
Kevin
- Attachments
-
- ps1crop_dfine_dss_v2_mercury_051221_small.jpg (1004.53 KiB) Viewed 1377 times
- Carbon60
- Way More Fun to Share It!!
- Posts: 14293
- Joined: Wed Mar 07, 2012 12:33 pm
- Location: Lancashire, UK
- Has thanked: 8523 times
- Been thanked: 8251 times
Re: Mercury sodium tail
Excellent, Kevin. That’s a superb image. I first saw this phenomenon on Spaceweather a few days ago. Fascinating.
Stu.
Stu.
H-alpha, WL and Ca II K imaging kit for various image scales.
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/
- marktownley
- Librarian
- Posts: 42494
- Joined: Tue Oct 18, 2011 5:27 pm
- Location: Brierley Hills, UK
- Has thanked: 20732 times
- Been thanked: 10427 times
- Contact:
Re: Mercury sodium tail
Interesting!
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
- JochenM
- Way More Fun to Share It!!
- Posts: 2839
- Joined: Tue Dec 10, 2019 2:26 pm
- Location: Belgium
- Has thanked: 1200 times
- Been thanked: 1619 times
- Contact:
-
- Way More Fun to Share It!!
- Posts: 2161
- Joined: Sun Jun 14, 2015 4:46 pm
- Location: France
- Has thanked: 1 time
- Been thanked: 2725 times
- Contact:
Re: Mercury sodium tail
Amazing. Well done !
Thanks for sharing.
Thanks for sharing.
Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
- rsfoto
- Way More Fun to Share It!!
- Posts: 6289
- Joined: Mon Jun 18, 2012 8:30 pm
- Location: San Luis Potosi, México
- Has thanked: 9677 times
- Been thanked: 5750 times
Re: Mercury sodium tail
WOW
regards Rainer
Observatorio Real de 14
San Luis Potosi Mexico
North 22° West 101°
Observatorio Real de 14
San Luis Potosi Mexico
North 22° West 101°
- KMH
- Almost There...
- Posts: 1044
- Joined: Sat Feb 22, 2014 4:45 pm
- Has thanked: 657 times
- Been thanked: 760 times
Re: Mercury sodium tail
Thanks, all. We learned about this on very short notice and were quite lucky to get some shots around the brightness maximum. Hopefully we can try again before too long, maybe having invested in a higher quality filter or even rigging up an occulting disc of some sort.
Here are a couple of links to interesting papers on the subject. The second one (unfortunately behind a pay wall) also shows images of the moon's sodium tail, and also the torus surrounding Jupiter (generated by Io), both with a 100mm scope. Will have to try Jupiter this coming opposition.
Kevin
https://agupubs.onlinelibrary.wiley.com ... 07GL032337
https://link.springer.com/article/10.10 ... 009-9314-y
Here are a couple of links to interesting papers on the subject. The second one (unfortunately behind a pay wall) also shows images of the moon's sodium tail, and also the torus surrounding Jupiter (generated by Io), both with a 100mm scope. Will have to try Jupiter this coming opposition.
Kevin
https://agupubs.onlinelibrary.wiley.com ... 07GL032337
https://link.springer.com/article/10.10 ... 009-9314-y
- Montana
- Librarian
- Posts: 34698
- Joined: Mon Oct 17, 2011 5:25 pm
- Location: Cheshire, UK
- Has thanked: 17888 times
- Been thanked: 8887 times
- p_zetner
- Way More Fun to Share It!!
- Posts: 1644
- Joined: Sun Mar 18, 2012 4:59 pm
- Location: Winnipeg, Manitoba, Canada
- Has thanked: 166 times
- Been thanked: 719 times
Re: Mercury sodium tail
I’ll repeat some of the comments above: WOW!
What a terrific, informative post and a fabulous capture.
I had no idea about this phenomenon.
Thanks for enlightening me.
Cheers.
Peter
MODS: Alexandra and Mark, would this be a better fit in the Spectroscopy forum?
What a terrific, informative post and a fabulous capture.
I had no idea about this phenomenon.
Thanks for enlightening me.
Cheers.
Peter
MODS: Alexandra and Mark, would this be a better fit in the Spectroscopy forum?
- KMH
- Almost There...
- Posts: 1044
- Joined: Sat Feb 22, 2014 4:45 pm
- Has thanked: 657 times
- Been thanked: 760 times
Re: Mercury sodium tail
Thanks again, everyone!
We will definitely try this again, maybe with a better filter. We also will try to image the sodium/sulfur cloud around Jupiter this opposition.
One question maybe someone here can help with. It might be helpful to use an occulting bar. I have seen explanations of how to do this with an eyepiece but not so much for imaging (at least at an amateur level). One of the links above shows a dedicated 1x assembly of two identical lenses with the mask at the focal point in between. This assembly is the first element in the optical train. Does anyone have any other thoughts on this?
Thanks,
Kevin
We will definitely try this again, maybe with a better filter. We also will try to image the sodium/sulfur cloud around Jupiter this opposition.
One question maybe someone here can help with. It might be helpful to use an occulting bar. I have seen explanations of how to do this with an eyepiece but not so much for imaging (at least at an amateur level). One of the links above shows a dedicated 1x assembly of two identical lenses with the mask at the focal point in between. This assembly is the first element in the optical train. Does anyone have any other thoughts on this?
Thanks,
Kevin
- ffellah
- Way More Fun to Share It!!
- Posts: 11276
- Joined: Mon Oct 27, 2014 6:46 pm
- Location: Westport, CT USA
- Has thanked: 9280 times
- Been thanked: 6125 times
- pedro
- Way More Fun to Share It!!
- Posts: 12313
- Joined: Sun May 01, 2016 8:26 pm
- Location: Portugal
- Has thanked: 14 times
- Been thanked: 6683 times
- Contact:
Re: Mercury sodium tail
Fantastic Kevin, amazing stuff
Pedro Re'
https://pedroreastrophotography.com/
https://pedroreastrophotography.com/
- Montana
- Librarian
- Posts: 34698
- Joined: Mon Oct 17, 2011 5:25 pm
- Location: Cheshire, UK
- Has thanked: 17888 times
- Been thanked: 8887 times
Re: Mercury sodium tail
This is indeed a fantastic topic Peter, it is probably relevant in both forums, so I will add a copy into the spectroscopy forum so you can find it both here and there in the future
Alexandra
Alexandra
- KMH
- Almost There...
- Posts: 1044
- Joined: Sat Feb 22, 2014 4:45 pm
- Has thanked: 657 times
- Been thanked: 760 times
Re: Mercury sodium tail
Thanks Alexandra! I'll be interested to see if anyone has any ideas. I'm continuing to look into both the coronagraph possibility and the physics of the tail formation and brightness variation.
Kevin
Kevin