Search found 5456 matches

by brian livesey
Wed Oct 21, 2020 10:18 am
Forum: Observing
Topic: observing from bed
Replies: 33
Views: 870

Re: observing from bed

Just to say Nigel, that you could go down a couple more notches in magnification on the 4-incher. From the sources I've read, the lowest magnification with a scope is 4D. That's to say four times the diameter of the aperture in inches. This would be 16X for a 4-incher.
by brian livesey
Wed Oct 21, 2020 10:01 am
Forum: Space exploration
Topic: Osiris-REX has landed.
Replies: 1
Views: 17

Osiris-REX has landed.

To the delight of NASA controllers, it's asteroid probe to asteroid Bennu, launched in 2018, has landed on the stony body, taken a surface sample, and is on its way back to earth.
by brian livesey
Tue Oct 20, 2020 8:26 pm
Forum: Gallery
Topic: The SUN - 20th October
Replies: 2
Views: 16

Re: The SUN - 20th October

Dammit Cliff, I missed today's prom. I was tempted to look through the PST this afternoon, but at the last minute decided not to. It was one of those days where the Sun popped in and out of passing cloud. I almost always find on days like today that by the time I get to the eyepiece, the Sun disappe...
by brian livesey
Mon Oct 19, 2020 8:59 pm
Forum: Observing
Topic: observing from bed
Replies: 33
Views: 870

Re: observing from bed

Yes Nigel, a 4-inch/f.5 refractor makes a good richest field 'scope. Ideal for the Orion Nebula the Perseus double-cluster and M31 in Andromeda, etc. :D
by brian livesey
Mon Oct 19, 2020 12:41 pm
Forum: General chat
Topic: books
Replies: 3
Views: 44

Re: books

You might like to consider Phillips Colour Star Atlas. The maps are very attractive and give the physical types of many stars. There's also plenty of interesting text for an atlas. I wouldn't like to part with mine. :D
by brian livesey
Mon Oct 19, 2020 12:06 pm
Forum: Observing
Topic: observing from bed
Replies: 33
Views: 870

Re: observing from bed

How's your 4-inch/f.5 refractor for chromatism Nigel? I have the same spec, but a Celestron. The chromatism is pretty strong on higher powers. I bought a Baader semi-apo filter to deal with it, but I reckon that it's only about 30 per cent effective. It also reduces some of the incoming light, in co...
by brian livesey
Sun Oct 18, 2020 5:11 pm
Forum: Gallery
Topic: Messier 13
Replies: 5
Views: 74

Re: Messier 13

A thousand apologies Ian for mistaking your image for a Smerral one!
by brian livesey
Sun Oct 18, 2020 11:17 am
Forum: Astrophysics
Topic: How an ice age begins and ends
Replies: 0
Views: 22

How an ice age begins and ends

A recent theory of how the ice age began challenges the theory of Milankovitch cycles, by saying that gases released by volcanic activity, dissolving rocks in mountain sutures, cooled the atmosphere. Now, a new theory complements the first by explaining how the last ice age ended. It's been known fo...
by brian livesey
Sun Oct 18, 2020 11:09 am
Forum: General chat
Topic: books
Replies: 3
Views: 44

Re: books

When you say "quality books", do you mean technical volumes or the more popular sort of, say, the Patrick Moore kind? The range of astronomy books is vast?
by brian livesey
Fri Oct 16, 2020 6:54 pm
Forum: Space exploration
Topic: Gateway to the Moon
Replies: 0
Views: 16

Gateway to the Moon

A company with sites in Bristol, Belfast and Oxfordshire, Thales Alenia Space, has done a deal with Nasa through the British Space Agency to construct a chemical refuelling station. The station will assist in transferring fuel to the Lunar Gateway space station that will orbit the moon and operate a...
by brian livesey
Thu Oct 15, 2020 11:12 am
Forum: Visual Satellite Observing
Topic: U.K. Gov. abandons its Global Navigation Satellite System
Replies: 2
Views: 35

Re: U.K. Gov. abandons its Global Navigation Satellite System

The cost of the unfinished project has far outstripped the planned budget, which is why the government has cancelled it.
by brian livesey
Thu Oct 15, 2020 10:47 am
Forum: Gallery
Topic: Messier 13
Replies: 5
Views: 74

Re: Messier 13

Gorgeous Brian, a very clean image.
by brian livesey
Wed Oct 14, 2020 11:28 am
Forum: Visual Satellite Observing
Topic: U.K. Gov. abandons its Global Navigation Satellite System
Replies: 2
Views: 35

U.K. Gov. abandons its Global Navigation Satellite System

After just 18 months into the project and at a cost of £64m,the Government has given up on it Global Navigation Satellite System. The project was intended to be an independent alternative to America's GPS and the EU's Galileo ( from which the U.K. is now excluded ). Now the Government is persuing th...
by brian livesey
Tue Oct 13, 2020 6:11 pm
Forum: Visual Satellite Observing
Topic: Earth to get a mini moon ..
Replies: 1
Views: 37

Re: Earth to get a mini moon ..

When we consider the age of the Earth and the great numbers of asteroids that have struck our planet, it seems strange that there are no near-earth asteroids that have gone into earth-orbit and circle us as mini-moons. Anybody any ideas about this? There has to be a reason/s why we don't see capture...
by brian livesey
Mon Oct 12, 2020 8:09 pm
Forum: Observing
Topic: Here come the Orionids
Replies: 1
Views: 32

Here come the Orionids

Although Orionids can be seen now, they arrive in force at the weekend, with rates at twenty or so an hour. The Orionids are swift meteors, as they meet the Earth more-or-less head on. This is in contrast to the apparently "slow" Taurids, that have to catch up with the Earth in its orbit. The Orioni...