New member, Jupiter question

[Dean Drumheller]

I'm new to ARAS, and especially interested in listening and learning.

Also, we're currently looking at H-alpha on both sides of Jupiter to measure radial V and rotational V, and within 3 km/s of SETI Jupiter Ephemeris Generator data. We have at 3 sets of data with similar results, so gaining confidence. It is challenging to place the slit equidistant from the edge, and keeping it stationary during the exposure.

For rotational V, we've had 11.5 km/s vs. 12.6 km/s found on Wiki
For radial V, we've had 22.7 km/s vs. 19.44 km/s for the same time, found on SETI Jupiter.

I would be interested if anyone has done similar measurements of Jupiter and the procedures and results.

We use an SBIG SGS and Vspec. 8" SCT @ 6.3 Look forward to watching the forums. -Dean

[Robin Leadbeater]

Hello Dean,

I've usually seen it done by aligning the slit along the equator of the planet. Then you can pick out the full velocity profile across the planet in one go by the slant of the reflected lines relative to the neon lines or even neater, relative to the telluric lines in the same image if you pick the right part of the spectrum. (In theory it might also be possible to pick out lines from absorption in the planet atmosphere eg Methane which should have half the slant of the reflected lines) I remember it was the second thing I tried, (using Saturn) with my LHIRES after looking at the solar spectrum.
http://www.threehillsobservatory.co.uk/ ... tra_28.htm
but there is a better writeup here (also using Saturn) on the original LHIRES site
http://www.astrosurf.com/thizy/lhires3/ ... t0001.html

Cheers
Robin

[Francois Teyssier]

Hello Dean,
Welcome on the forum
Perhap's an answer to your question from Shelyak site : http://www.shelyak.com/dossier.php?id_dossier=16

All the best,

François Teyssier

[Dean Drumheller]

Thank you Francois and Robin. I don't read French but maybe I'll find this in English on Shelyak site.
Trying to understand the idea of locating the slit along the equator ! Sounds very interesting.

Meanwhile, I found a trick to improve guiding, for a very stationary slit during exposures, and now starting to image Saturn and rings.
Thanks -Dean Drumheller

[Robin Leadbeater]

Thank you Francois and Robin. I don't read French but maybe I'll find this in English on Shelyak site.

Hi Dean,

If you click on the "english version" link near the top right and then step back to the previous page it should appear in English. I understand the SGS is significantly lower dispersion than the LHIRES with a 2400 grating so the effect may not be so obvious.

Robin

[Valerie Desnoux]

Welcome on the spectro place, Dean !
Hope you will find the support you need from this fantastic and "all-around-the-world" community.

I did some run on Saturn and guess what, I put the slit the wrong way...
V.-