[Robin Leadbeater]

Have the attachments been stripped from pre uplift posts ? eg

https://britastro.org/forums/topic/using-miles-stars-to-check-spectrum-quality#post-577636

Also a repeat plea for a return to full html editing and images and attachments in posts.

Cheers
Robin

[Robin Leadbeater]

Testing embedding external links
http://www.threehillsobservatory.co.uk

would it be better to open these in a new tab ?

• This reply was modified 2 years, 12 months ago by Robin Leadbeater.

[Robin Leadbeater]

I don’t like the way if you add a link in a forum post to a page in the BAA website it embeds a huge screen shot of the page. How do I stop it doing that so I can just have the link embedded in the text? (The old system with full editing allowing choice of fonts and links with options to open in a new tab was much better IMO)

• This reply was modified 2 years, 12 months ago by Robin Leadbeater.

[Robin Leadbeater]

I notice some content which was free access without login previously is now restricted. Is that a policy decision ?
eg in the past I have referred to these free access video presentations of mine on other forums
https://britastro.org/videos/using-low-resolution-spectroscopy-to-confirm-supernova-discoveries-2
https://britastro.org/videos/pushing-the-limits-using-commercial-spectrographs-2

Robin

[Robin Leadbeater]

“The forum is all linear now – we’ll look into having quoted replies.”

Testing the forum linearity

Ah ok, thats good

Robin

• This reply was modified 2 years, 12 months ago by Robin Leadbeater.

[Robin Leadbeater]

Can we have the “last post” button on the forum topics back please ? Although not perfect it at least gave the chance to find replies to earlier posts in the topic which are otherwise missed as they don’t appear at the bottom of the list.

Personally I much prefer the format used by most other forums like Cloudy Nights, Stargazers Lounge etc where all posts in a topic appear sequentially with the option to quote and link the specific post being replied to.

[Robin Leadbeater]

On the home page when logged in, the big “Observe” and “Explore” buttons both go to the same place (the image gallery). Would it be better to replace one of them with the “Discuss” button ?

[Robin Leadbeater]

There appears to be two login options at the bottom of the forum pages. The square button goes to a wordpress login rather than direct to the sheepcrm login

[Robin Leadbeater]

Logging in every time is getting tedious and the login always taking you back to the home page instead of staying on the page you were on adds to the frustration. Definitely need a keep logged in cookie

[Robin Leadbeater]

Forum posting form seems to be plain text only. How are images, links, attachments added ?

[Robin Leadbeater]

On mobiles the login option is right at the bottom of a long list, neededing to scroll down several pages. Suggest bringing it to a prominent position at the top

[Robin Leadbeater]

Another post has disappeared 🙁

EDIT It may be related to adding complete web addresses. The post stayed when I shortened the addresses as below

Trying again

Some content which was free access previously is now members only. Is that a policy decision ?

eg
….videos/pushing-the-limits-using-commercial-spectrographs-2
….videos/using-low-resolution-spectroscopy-to-confirm-supernova-discoveries-2

which I have linked to on other forums

Cheers
Robin

• This reply was modified 3 years ago by Robin Leadbeater.

[Robin Leadbeater]

Just added a post here, then edited it but it has disappeared ???

Robin

EDIT It was about multiple wrongly directed links on
https://britastro.org/section_information_/equipment-and-techniques-section-overview/spectroscopy
EDIT no idea where that graphic is from I just entered the full address of the page with the wrong links

….section_information_/equipment-and-techniques-section-overview/spectroscopy

• This reply was modified 3 years ago by Robin Leadbeater.
• This reply was modified 3 years ago by Robin Leadbeater.

[Robin Leadbeater]

Multiple wrongly directed links from
https://britastro.org/section_information_/equipment-and-techniques-section-overview/spectroscopy

Spectroscopy workshop at the Norman Lockyer Observatory October 2015
Alpy 600 Spectrograph workshop, Kintbury, October 2016
Observers’ Workshop on Variable Stars, Photometry and Spectroscopy, 29 Sep 2018
Using low resolution spectroscopy to confirm and classify supernovae (video from BAA meeting January 2018)
Starting in Spectroscopy (video from BAA/AAVSO joint meeting on variable stars, July 2018)
Pushing the limits using commercial spectrographs (video from BAA/AAVSO joint meeting on variable stars, July 2018)
Towards full automation of high resolution spectroscopy (video from BAA/AAVSO joint meeting on variable stars, July 2018)
HST CALSPEC calibrated absolute flux spectra for converting relative intensity to FLAM units

EDIT No idea where the graphic came from, I just entered the address of the page
“https://britastro.org/section_information_/equipment-and-techniques-section-overview/spectroscopy”

• This reply was modified 3 years ago by Robin Leadbeater.

[Robin Leadbeater]

Is there a way to stay permanently logged in like on the old site ?

Thanks
Robin

[Robin Leadbeater]

Even allowing for the trailing, that looks quite a bit fainter than the mag 13 Nick reported on 5th. The adjacent bright star  is  SDSS J081542.48+144838.9  at g mag 15 

[Robin Leadbeater]

A low resolution spectrum taken last night (3 hours exposure) showing a very broad H alpha emission with velocities up  to +-12000km/s

https://britastro.org/observations/observation.php?id=20220207_205606_9d5b2259183a3d41

Cheers

Robin

[Robin Leadbeater]

Thanks Nick,

I’ve found the original preprints of Comets II are available to download from the Lunar & Planetary Institute. Plenty of reading there !

[Robin Leadbeater]

Hi Maxim,

Thanks for the reference. ( I am on a steep learning curve here !) I can understand how the Swings effect could enhance or suppress the strength of the resonance emission due to the velocity relative to the sun (The distributions are normalised relative to the intensity at the coma centre so don’t show the absolute strengths) but I don’t follow how that could alter the shape of the CN distribution. Would this be due to the resulting radiation pressure sweeping the CN away from the coma into the tail,  like  Sodium in 2020 F3 ?

 That reference to parent molecules and the Haser model on your Fernandez page 68  did remind me of some comments from Jeff Morgenthaler of the IoIO team on my F3 cross sections.

 “CN is produced from a parent molecule, likely HCN.  The combination of that double process ends up extending the lifetime of CN to photodissociation (destruction by sunlight).  I have not done the conversion of angular scale to distance from the comet on your night of observation, but the characteristic scale length of CN emission when comets are at 1 AU from the sun tends to be about 20,000 km.  C2 is a little weirder in terms of parent molecules.  It seems to have two dominant ones, leading to a flat profile in the inner few thousand km of the coma.  Then it drops off with a profile slightly shorter than CN.”

So perhaps I need to consider the effect of sunlight on both  the rate of production and destruction of CN and C2 and  follow up on the Haser model.

 

Thanks

Robin

[Robin Leadbeater]

“Is CN also broken down by sunlight, though at perhaps a slower rate than C2 ?”

Actually, answering my own question  it looks like that cannot be the explanation as CN is seen  widely distributed in the cross section  through the tail of 2020 F3. Any ideas of what is going on? 

[Author]

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