Forum Replies Created
-
Posts
-
According to my university notes angular seperation of red & blue images from atmospheric chromatic abberation is:
¬4 x 10^-6 x tan angle from zenith. Angles are in radians.
Based on a 450nm refractive index of 1.0002796 and a 650nm refractive index of 1.0002758.
Think it was Space X’s Transporter-14, Mel Gigg captured a nice video of it. Alas I was in bed. https://www.youtube.com/watch?v=RDe-gmF1dxM
Interesting!
Looks like a 4% chance of a visit to Australia on Dec 22nd 2032. The view of the Earth from the Moon at possible impact time.
Attachments:
Very interesting to read Paul’s report in the latest Journal. It reminded me of the cover of a Patrick Moore SF book that I took out of the library when I was an excitable 10 year old. The illustration is by David Hardy.
Attachments:
Up at 2.30am, clear, drove 4 miles to get a low NE horizon, my Seestar’s view at 3.30am. A little frustrating!
Attachments:
Good news. C/2025 F2 (SWAN) is now in Seestar catalog. No Seestar star hopping for me tomorrow morning.
Attachments:
Glad it now has a name.
4 am alarm failed to wake me this morning so was late going on duty. Brightening sky rapidly halted play. 14 min 50 sec of 10 sec subs with Seestar S50. Tail was much less visible than yeaterday but yesterday alarm woke me and managed nearly 25 minutes.
Attachments:
Some good news from publicity. ZWO have added it to Seestar’s catalog.
Attachments:
I to would be very interested in such a script. Have been using a Seestar to keep on eye on T CrB since June whenever circumstances allow. As of this morning I have 25,094 images of T CrB not in outburst. I am now using an S30 instead of an S50 which I think gives better results. Fewer rejected frames due to shorter focal length and smaller aperture means the sensor would saturate later when it goes into its long awaited outburst.
Have you seen this Jeremy? Has more than a whiff of numerology about it. Of course I do not believe in numerology, checks my diary for March 27th. https://www.researchgate.net/publication/385381254_When_will_the_next_T_CrB_eruption_occur
Not sure about that David. Eye has quite a large airy disc. This is maximum permissible exposure of a laser beam, a point source. Solar constant at Earths surface is about 100mW per square centimetre. Even factoring in that sun is not a point source viewing it naked eye is certainly hazardous. If supernova Betelgeuse was as bright as full moon then it would be 340,000x less.
Attachments:
This is precisely why I have very muddy knees after a late night / early morning drive out to a dark sky. 6D, no flip screen.
Attachments:
Paul,
Have had a Seestar for about a year, very very happy. You have to set it to save individual frames internally. FITS files are stored in its internal memory in a sub folder. If it is in station mode you navigate to it on your network and download files. You can do this as it’s acquiring data.
Steve
Hi Gordon, have you thought about an equatorial tracking platform? I use mine with my 8in and 12in Dobs, set up is easy. Tracking not really good enough for deep sky imaging but fine for lunar and planetary.
Steve
Gary,
Thanks for that. Most interesting.
It was Jeremy’s talk in June 2023 that sparked me delving into The Times archive. I wanted to see if there was any sign of John Birmingham’s lost discovery letter.Alas no.
Steve
Might be of interest. The Times, May 21st 1866 and February 13th 1946.
Hoping for more coverage than 1946 in 2024, or 2025 or 2026?
Attachments:
