Yesterday I presented my beginners guide to observing and buying a first telescope at the Inverness Urban Astronomy gathering. Here is my 2020 recommendations for good starter equipment.
1. Binoculars: 8x40s or 10x50s. Prices from £50 for decent ones. I personally use Olympus DSP1s and we’ve purchased these for both the Abriachan and Merkinch outreach programmes.
2. Telescope: Skywatcher 150mm or 200mm dobsonian. Simple to use with great performance. Prices from £175. Get the 200mm if you have the space and extra cash to spend.
3. Books: Left Turn at Orion and Stargazing for Dummies. From £15 each.
4. A red light LED headtorch. From £6 if you go to Tesco’s. Up to £30 for a good quality one.
5. A planisphere. They cost around £10 and can be found in good book stores.
Of all the items above I’d say binoculars are the most important. People are often surprised to discover I do over 90% of my observing with a simple pair of 8x40s. You can read an earlier post on the merits of hand held astronomy here.
As the constellation Virgo rises earlier and earlier after darkness we’re entering a time of great opportunity for observing distant galaxies.
Within the upper right hand stretches of Virgo are giant clusters of galaxies strung out in loose bundles. Some of these very distant galaxies can even be see in bioculars if you’re under excellent dark skies. Telescopes will pick them out better and it’s here that aperture rules. Faint galaxies need big objective lenses to see clearly.
More galaxies are scattered to the lower right of the constellation too, including the famous Sombrero galaxy (pictured).
The Sombrero Galaxy
Your fleeting glances will look nothing like Hubble’s post processed images but you will be witnessing the hazy light from billions of ancient stars for yourself. These galaxies are island universes just like our Milky Way, and contain many billions of stars.
Globular clusters are some of the best deep space objects to view with a video telescope setup. These tightly bound swarms of stars orbit our Milky Way at a distance of 100,000 lights years or more and contain many more older stars than open clusters. The density near the core of these stellar globules is very pronounced indeed, such that any inhabitants of a planet deep inside one would see a night sky peppered with incredibly bright stellar neighbours. This artist impression from William Harris and Jeremy Webb illustrates the point beautifully.
What the sky might look like inside globular cluster ’47 Tucana’ where nearly 600 thousand stars jostle within a volume of space only 120 light years across.
I planned to video the famous M3 globular tonight after seeing its relative high altitude and fortuitous position in SkySafari, and noting with some relief how clear and enticing the moonless sky looked.
After very little effort, and with a short 3 second integration time, I was able to watch this spectacular sight slowly materialise in the video monitor
M3 contains over 500 thousand suns at a distance of 34 thousand light years from earth.
This image is incredibly bright and vibrant compared to naked eye views of M3 and is only slightly marred by a few visual artefacts due to the sensor technology. The bloated white dots at the widest periphery of the image are not stars but hot spots due to the video chip heating up during long exposures. Despite this I’m sure you’ll agree the view is a triumph of video observing, readily revealing the awesome density and structure of the cluster.
There are over 150 of these satellite clusters orbiting our Milky Way galaxy and their formation is the topic of excited debate. The fact they harbour such a high proportion of older stars suggests they were some of the first stars to evolve within the overall galactic neighbourhood.
As far as the question of technological life existing within these systems, the chaos from closely interacting stars (on average only 1 light year apart) might prove an unfavourable environment. Stars and planets in such a system would be under constant perturbation from nearby neighbours imparting gravitation ‘tugs’, resulting in unstable planetary orbits.