How wide is your hand?

Most people who have an interest in astronomy (or atmospheric phenomena) will know the usual tricks for measuring angles and distances in the sky. The general idea is that you hold your hand at arm's length and, using difference parts of your hand, held in different ways, get a reasonable measure.

But how accurate is this approach?

Robin Scagell, via a post on the SPA BB, aims to find out:

I would like to find out what is the average dimension of a hand span in degrees. It is often said that a full hand span at arm's length is 20°, but I would like to get some accurate figures on this. So I have checked the distances between several well-known stars in the early evening sky and would like people to go out and test it for themselves.

Have a look Robin's post for full details of the experiment.

SPA Convention 2007

It's almost here! One more day and it's the SPA convention 2007.

I'll be heading out to Cambridge rather early tomorrow morning (about 0600UT) as I'm going to lend a hand setting things up. As such it should be a long, but enjoyable, day.

The main themes for this year's event are astrophotography and planetary astronomy and talks include:

• Pixel Magic - Getting the best from your Astro Photography


• Saturn and the Terran Planets


• Venus and the Venus Express Mission


• Instruments for Planetary Observing

There's also going to be a few trade stands there if there's money burning a hole in your pocket (I'm pleased to see that Aurora Books will be there — I know Martin from the days when I was a member of York Astronomical Society and it's always nice to catch up).

If you're going to be there do keep an eye out for me and tap me on the shoulder and say hello. I'll probably be wearing a name badge and, if it helps, the picture of me chimping over on my photo.net page should give you a bit of a clue about how I look these days (chances are that I'll be chimping away there too <g>).

Pluto is a Planet (Says New Mexico)

Seems that the state legislature of New Mexico has decided that Pluto is a planet.

Apparently March 13th 2007 (only 2007?) will also be "Pluto Planet Day".

Not Just Red - Infrared!

Once again Pete Lawrence comes up with an interesting spin on astrophotography. Via this article on the SPA BB:

The eclipsed Moon was quite dim in visible light but reasonably bright in IR. I managed to grab 4 quadrant shots of the Moon at the time of totality, mosaic them together and then overlay a DSLR colour shot on to. In this way the IR provides the luminance information while the DSLR shot provides colour. The result is an IR biased colour shot of totality. As the IR signal was reasonably bright, the details on the Moon could be imaged with a reasonable amount of sharpness.

2007-03-03_23-28-20_IR742-natural.jpg

World-Wide Star Hunt

Back in December last year I reported on the BAA/CfDS/CPRE star count. Stuart picked up on this and, in the comments on Stuart's blog, Ian sort of got to thinking about an international effort to do something similar.

This morning I had an email from Robin Scagell, alerting me to Globe at Night. Here's an excerpt from the press release:

The international star-counting activity known as GLOBE at Night returns from March 8-21 in two flavors: the "classic" GLOBE at Night exercise that anyone can have fun doing with their unaided eyes, and a new effort to obtain precise measurements of urban dark skies using digital sky-brightness meters.

The GLOBE at Night 2007 program is intended to build upon the worldwide participation sparked by the first GLOBE at Night campaign in March 2006. This inaugural effort drew more than 18,000 citizen-scientist participants in all 50 U.S. states and 96 countries worldwide, who submitted nearly 4,600 observations of the darkness of their local night skies during the 10-day event. The program is designed to aid teaching about the impact of artificial lighting on local environments, and the ongoing loss of a dark night sky as a natural resource for much of the world's population.

It seems they're also using Orion as the patch of sky for doing comparisons and, helpfully, they have a set of magnitude charts to help in estimations (and don't you just love the fact that they've produced just such a chart from a cloudy night).

There's even a nifty little tool for testing your estimation ability.

This all sounds like just the sort of thing that Ian will like.

Lunar Eclipse Movie

Tim Haynes (friend and BOFH for the machine I host my websites on) was also out on Saturday night, observing and photographing the total lunar eclipse.

Not only did he take a whole load of images of the event, he also produced a pretty neat video of it too:

It's a shame that the Moon has got squashed in the YouTube version (the original looks better) but, that aside, I think it's a pretty neat record of the event.

What the hell is happening?

After reading this entry on Rich Daley's blog I was reminded of something I was thinking about on Saturday night.

What do people who have no knowledge or interest in astronomy make of something like a total lunar eclipse? Here in the UK you'd be hard pushed to find someone who didn't know that a total solar eclipse was coming, it's such a rare occurrence that it would be reported everywhere for days prior to the event (as it was in 1999). Most partial solar eclipses won't be noticed, most people who haven't been told about it won't know it's happening.

Partial lunar eclipses probably aren't noticed either, I'm guessing that most people, even if they noticed that part of the Moon was missing, would assume it's just one of the Moon's phases (it's not uncommon for people to think that the Earth's shadow is responsible for the Moon's phases).

But a total lunar eclipse seems a little different to me. It's one of those events that can be reported in such a way that people don't know it's happening (personally I only ever saw mention of Saturday's eclipse, in passing, during weather reports on the BBC news) while, at the same time, is very obvious to the naked eye – if you were out and about on Saturday night you'd be hard pushed not to notice that the Moon was full but wasn't bright and was a very strange colour.

I wonder what Rich's bouncer was really thinking. I wonder what ideas had gone through his mind. I wonder what possible reasons he'd entertained. I wonder how many other people were in the same position last Saturday, faced with something out of the ordinary, something impossible to ignore, something needing an explanation. I wonder what hypotheses they entertained.

Lunar Eclipse 2007-03-03 - Log now up

I've now uploaded my observing log of the total lunar eclipse.

Lunar Eclipse 2007-03-03

As I'd hoped a couple of days earlier the weather played ball and last Saturday night was nice and clear.

So I got to observe the whole of the total lunar eclipse. For some detail of my observing session have a look at the short report I wrote on the SPA BB this morning – I'll be adding my full observing log later on today.

I didn't bother to attempt any photography (other than a few afocal shots with my mobile phone, through the Antares 905 – a small example can be seen above), I just wanted to observe and enjoy the whole event (and it's not like it wasn't going to get photographed by anyone else <g>).

I thought totality was reasonably dark, personally I'd rate it as L2 on the Danjon Scale.

Just one downside to the whole event: I managed to stand on my glasses and scratch them so badly that they're not really useful any more. Thanks to that I think this has been my most expensive observing session yet. It was also kind of annoying to find myself observing a great naked-eye event and find that the only bit of optical equipment I had with me that wasn't working was.... my eyes.

There was a nice little bonus to the whole evening though. After we'd packed up (after last umbral contact), and because there was so much dew on the grass, I stood with my back to the full Moon and noticed a nice, if faint, example of Heiligenschein.

Welcome to March

So, it's March again. March is sort of important to me in astronomy for a few reasons:

• I purchased my Sky-Watcher Explorer 130M in March 2005.


• I Purchased my Antares 905 in March 2006.


• I started regular solar observing in March 2006.


• I observed my first partial solar eclipse (first since starting to keep observing logs) in March 2006.

All being well March should be good this year too. First up, weather permitting, is Saturday's lunar eclipse. The current forecast from the Met Office is for clear skies on Saturday night.

Secondly, a week on Saturday, it's the 2^nd SPA convention. I'm really looking forward to that. The first one in October 2005 was very enjoyable so I'm expecting this to be a good day out too.

So far it's been a terrible start to the year, other than a couple of brief views of comet McNaught, and a brief session observing the Moon and Saturn, I've hardly been out so far this year. I'm hoping that the next two or three months offer up some good nights before the long days of summer take over.

Collapse of Rover hits UK astronomy?

According to this story on the BBC website:

UK science has become an unexpected victim of the Rover collapse as funds used to soften the impact of the failure were clawed back from research.

The Department for Trade and Industry said it faced financial pressures that required it to re-balance its spending.

Ongoing costs related to the loss of the Rover car company and the rescue package put together for British Energy were cited as causes for the shortfall.

It means £68m given to the UK Research Councils by the DTI will be taken back.

Towards the end of the article there's a list of various research councils and the impact it will have, one of them is:

Particle Physics and Astronomy Research Council £3.1m

That can't be good, can it?

Next week's lunar eclipse

Like Will, I'm already thinking about observing next week's lunar eclipse.

All being well, weather permitting (sadly the 6 to 15 day forecast from the Met Office doesn't give much of a clue about what to expect), I'm hoping to join a fellow observer a Woodland Waters (somewhere we've used once so far and were very happy with). The horizon there is pretty good and should give an unobstructed view of the whole event.

Even though I now own a dSLR it's unlikely that I'll be taking any photographs of the event due to the fact that I don't have the kinds of equipment that make it worth it, although I might try something — during the last lunar eclipse the fact that I only had a compact digital camera didn't stop me from trying to make some sort of photographic record.

Visually I'll probably be using a 10x50 binocular and the Antares 905. Pretty much all of my observing will be visual and, of course, I'll be keeping a written record of the event.

Fingers crossed that the weather plays ball again...

Sir Patrick's Day?

While it's nowhere near as odd as some e-peitions, this one caught my eye for the obvious astronomy connection:

We the undersigned petition the Prime Minister to Mark the 4th of March as a National Holiday in honour of Sir Patrick Moore's Birthday.

Sir Patrick Moore's extensive contribution to the rich scientific heritage of this nation should be rightfully recognised. We believe a National Holiday on the date of his birth: March 4th, would prove an apt and just cause for celebration and merriment as well as providing much appreciation of the scientific world.

Not that I'll be adding my name (mostly because we don't need any more public holidays in the UK, but also because I can think of better people to honour if such a thing were ever to be done).

The UK's own space program

Last Sunday evening I was treated to one of the best TV moments ever: Top Gear (I really don't care for cars much, but Top Gear isn't really about cars anyway) kicking off the UK's very own space program (yes, yes, I know, we used to have one):

For anyone who doesn't know what that actually is, it's a Reliant Robin.

That alone was worth the cost of this year's licence fee.

Dobsonian vs Equatorial

Via this post on the SPA BB:

Hmm, okay...

No more Night Sky

Stuart is reporting that Night Sky magazine will be no more. That's a real shame.

I first noticed the magazine, here in the UK, back in early 2005 and I've been buying it ever since. While it is more of a "beginners" magazine and I probably don't really count as a "beginner", I always found it to be an enjoyable read.

I hate Pete Lawrence

Well, okay, I don't really hate Pete Lawrence, but just when you think he can't get any more talented, or lucky, he goes and does something like this.

That's just showing off!

Astronomy Now, and some other bits

I had a parcel turn up today. In it was a copy of the March edition of Astronomy Now and a copy of the Astronomy Now 2007 Yearbook.

I hadn't ordered them.

This was AN's way of saying thanks for me letting them use a version of this post in an article of reports about Comet McNaught.

The free copy of the magazine was expected, but the free copy of the yearbook wasn't. I thought that was rather nice of them.

---

I've not done much in the way of observing in the past few weeks. I've not even managed much solar observing thanks to the weather. We did have a clear spell last night and I did wander out to have a look at the skies with a view to getting the EOS 400D out and possibly doing a little more constellation photography but cloud rolled in while I was assessing the sky.

Which sort of fits in nicely with the current news about Mira. It would be neat to get some shots off of that area of sky, then take some more later on down the line and compare the images.

A little bit of astrophotography

On Saturday evening I finally caved in and, while I had a space moment, I decided to give my Canon EOS 400D a quick go under the stars.

Conditions weren't ideal, mist was starting to form, but I dragged the tripod and camera out anyway. I played around with different exposure settings and generally got to know some of the features of the camera that I might want to use if/when I do some astrophotography (I'm more interested in using the camera for "straight" photography than I am astrophotography — I think I'm still more into observing than I am photographing).

Probably the best of the bunch was this one of Orion. It's trailed a little (no surprise) and I think the focus is a little off too, but M42 is clearly visible and, I think, I even managed to catch a faint meteor (look in the top half of Orion's "body").

Sundogs and Circumzenithal Arc

This afternoon I was lucky enough to catch a display of a pair of sundogs and a circumzenithal arc. The arc was rather faint, nowhere near as good as the last display I saw. Despite this I grabbed my camera and tried to record what I saw.