Search found 392 matches

by DRatledge
Sun Apr 05, 2020 8:51 am
Forum: General - Discussion
Topic: Planetary Exercise
Replies: 2
Views: 53

Re: Planetary Exercise

Peter, I did give some big clues as how to calculate it and I cannot really spell it out without spoiling it for others. Remember I said assume Eris hasn't moved - you can also assume the background stars haven't moved so all that has moved is the Earth. If you draw a plan of that then it should bec...
by DRatledge
Tue Mar 31, 2020 10:57 am
Forum: General - Discussion
Topic: Planetary Exercise
Replies: 2
Views: 53

Planetary Exercise

How far away is the minor planet ERIS? This was an exercise I set recently for Bolton School Astronomy group. Its distance can be estimated with simple maths using the image below. This is a composite of two images taken 4 days apart and ERIS is shown in its two positions. The answer is in Astronomi...
by DRatledge
Thu Mar 26, 2020 1:50 pm
Forum: Astrophotography
Topic: Comet Atlas - first try
Replies: 0
Views: 59

Comet Atlas - first try

Predicted to brighten considerably next month but I thought I had better have a try last night (25 March). It has a good tail though already. Below is a very rough stack of 26 x 4 minutes on the Comet so the stars all but disappear. Need to clean this up, get rid of the noise, add it to the star fie...
by DRatledge
Sun Mar 22, 2020 9:28 pm
Forum: Astrophotography
Topic: Bulls Eye
Replies: 2
Views: 235

Re: Bulls Eye

A second clear night - wow. But another Bulls Eye!
PS the object is too faint to register in this single image - I hope it appears when I add them all together.
by DRatledge
Fri Mar 20, 2020 9:03 pm
Forum: Astrophotography
Topic: Bulls Eye
Replies: 2
Views: 235

Bulls Eye

I thought aeroplanes were no longer flying? First decent clear night for weeks and first shot I get a bulls eye!
by DRatledge
Sat Oct 12, 2019 6:20 pm
Forum: Astrophotography
Topic: CCD Astronomy – the End of an Era?
Replies: 0
Views: 3694

CCD Astronomy – the End of an Era?

It looks like we are coming to the end of CCD astronomy – well at least for us amateurs. Sony have signalled they have stopped developing CCD imaging chips and now On Semi (formerly Kodak) have just announced they are terminating production. This includes the popular KAF range of sensors found in ne...
by DRatledge
Wed Jun 05, 2019 6:05 pm
Forum: Astrophotography
Topic: Fast moving star
Replies: 0
Views: 3282

Fast moving star

I first imaged Hubble’s Variable Nebula 18 years ago in 2001 and returned to it again this year. However, when I was comparing images I noticed a star had moved. I checked Edwin Hubble's famous 1949 image and this star was even further to the north back then.
by DRatledge
Fri Mar 29, 2019 2:11 pm
Forum: General - Discussion
Topic: Clocks forward in the Stone Age
Replies: 1
Views: 2296

Clocks forward in the Stone Age

If you think it’s a pain moving your clocks forward tomorrow night just imagine what it must be like at Stonehenge!
by DRatledge
Fri Mar 01, 2019 12:03 pm
Forum: Member Observations - Blogging
Topic: Stars in Orion - Ross's Survey
Replies: 5
Views: 5449

Re: Stars in Orion - Ross's Survey

Had another go at counting the stars again but I had help this time from my 11 year old grandson. He could see 12. We checked them against a star map and his faintest was the red star just below the belt at magnitude 5.9. The faintest I could see was magnitude 3.8 - that's the one below the left end...
by DRatledge
Sun Feb 10, 2019 10:56 am
Forum: Astrophotography
Topic: Asteroid 95 Arethusa
Replies: 0
Views: 3684

Asteroid 95 Arethusa

Noticed something was moving on this image on 2nd February 2019. Checking the asteroid database then it turned out to be asteroid 95 Arethusa. Always worth checking. It is about 100 miles across.