Friday 6 April 2012

Orion the hunter (and a Close Encounter of the Third Kind .....)

Orion is one of the most conspicuous, and most recognizable, constellations in the winter night sky - with the bright red Betelgeuse in the top left corner, the three stars of Orion's 'belt', the Orion nebula just below it and Rigel, the constellation's brightest star, in the bottom right corner.



The fiery red star below, Betelgeuse, is classified as a Class M red supergiant, one of the largest stars known. Strange as this may seem, fiery red usually indicates a cool star that is losing its radiation and dying out, while cool blue stars are the hottest, youngest stars. Betelgeuse is in fact in the last stages of its life and is expected to go supernova any time in the next million years (which is a very short time in stellar terms).



By contrast, right at the opposite end of Orion, is a bright pale blue star, Rigel. Rigel is a Class B blue supergiant. While blue supergiants are much smaller than their red counterparts (like Betelgeuse), they are amongst the hottest and brightest stars in the known Universe.



The three stars in the 'belt' below are, from left to right, Alnitak, Alnilam and Mintaka. And right below the belt is Orion's 'sword', where the Orion Nebula is located.



And just minutes after I took the image above, a strange alien craft flashed past right out of where the Orion Nebula is located - you can see the light trail left by it in the right bottom corner of the image below. Though the regular pattern of red lights of the Unidentified Flying Object may indicate that it is probably not as unidentified as I thought - this is the tell-tale signature of the warning lights of a very Earth-bound aeroplane.




Charioteer of the skies

The constellation Auriga is dominated by the bright star Capella and looks like a distorted pentagon. The name Auriga is Latin for 'charioteer' - its stars form a shape that was thought to resemble the helmet of a charioteer. Photo taken on an Olympus Camedia 2040Z piggy-backed on the telescope.




Capella (Alpha Aurigae) below is the brightest star in Auriga and the third brightest star in the northern hemisphere, after Arcturus and Vega. Although it appears to be a single star visually, spectroscopic observations have revealed that it is actually a star system of four stars in two binary pairs Capella means "small goat" - Auriga is usually pictured as a charioteer wielding a whip in one hand and holding a goat (Capella) and her two kids in the other. Photo taken afocally using a 10mm eyepiece on the telescope.


Eta Aurigae and Zeta Aurigae below are the 'kids' of Capella's goat. Epsilon Aurigae at the top is an unusual eclipsing binary system - it brightens then dims every 700 days due to being obscured by a huge dark disk orbiting an unknown object. Photo below taken afocally using a 10mm eyepiece on the telescope.






Menkalinan (Beta Aurigae) below is actually a ternary (triple) star system, although the light that the star system releases forges the appearance of a single star in the night sky. The third star, Beta Aurigae C, is a red dwarf star that is invisible to the naked eye. Photo taken afocally using a 10mm eyepiece on the telescope.




The Seven Sisters

The Pleiades, or Seven Sisters are among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky. These shot was taken by me on October 2011, just with my Olympus Camedia C4040-Z piggy-backed on the telescope - see, you don't even need a telescope do stargaze!


Pleiades as you would see it with the naked eye looking over the horizon 


Next time you're out looking up at the night sky, try and see how many stars in Pleiades you can actually count. While it's called the Seven Sisters, you'd probably be able to see only six stars. In Greek mythology, the missing 'Sister' is Merope and you can't see her because she has hid herself in shame because she was the only sister who married a mortal human and not a god.
 





The Pleiades in Japanese is 'Subaru' - and the car manufacturer's logo is inspired by this star cluster!





Here comes the Sun

The mid-day sun in October 2011, as seen through a Meade ETX-80 telescope, using a Baader AstroSolar safety film over the telescope objective and a Neximage CCD Imager (coupled to a focal reducer) to capture the video. Despite being a cloudy day (this IS England!), the sun spot activity can be clearly seen - 3 large ones on the left and at least one small one in the middle. Midway in the video, you'll also be able to see the vapour trail left by a passing aircraft as its blown by the wind!




Detach the reducer lens and stick on a 2X Barlow lens, and you'll be able to zoom in on the action in the sunspots. The dark core (umbra) and lighter filamentary outer region (penumbra) are clearly visible. At the beginning of the video, three much smaller sunspots can be seen to the left of the large ones and another smaller sunspot can be seen to the right near the end. Ignore the two or three 'dust bunnies' on the video (blobs of dirt on the imaging chip that do not move with the passage of the sun).




I took a few still images a few days later, below:




And, to verify my results, below is the equivalent satellite picture from NASA's Solar Dynamics Observatory (SDO) at http://sdo.gsfc.nasa.gov/ . I suspect they used slightly more expensive equipment than I did ;)



Jupiter Rising

Taken in September 2011, this was my very first attempt at astro-videography: Jupiter and its Galilean moons (from left to right: Io, Europa, Ganymede and Callisto). Video through my small Meade ETX-80 80mm achromatic refractor telescope, using a Celestron NexImage charge-coupled device (CCD) camera and AMCap video capture software. 






Reducing the gain, gamma, brightness and other settings on the video camera will reveal the rings of the planets (though you will lose the moons as a result)





 This video was processed with Registax astronomical image stacking software to produce a much-clearer still image below.



Essential software

When starting stargazing, don't just think hardware  - think software too! And unlike the hardware, you don't need to pay an arm and a leg for a lot of astronomy software  - in fact, most of the really good software is as free as the air you breathe. Top of the list of software you'd need should be planetarium software. This is a package called Cartes du Ciel (Skycharts) which not only maps the sky at your current location but also allows you to remotely control the telescope as well - just click on a target on the screen and the telescope swivels immediately to it! Cartes du Ciel is completely free and available at http://www.ap-i.net/skychart/



And if you fancy a little lunar exploration, a moon atlas would be useful. This is the Virtual Moon Atlas, available free athttp://www.ap-i.net/avl/en/start



If you want to capture video with a CCD imager, you'll need video capture software. This is WxAstroCapture - specifically designed for astronomical use and free from http://arnholm.org/astro/software/wxAstroCapture/



And once you have that video, you'll want to do some image stacking and processing on it to produce high-quality high-resolution images. The industry standard is Registax - another free product and available at http://registax.astronomy.net/





Boys and their toys: Telescope Accessories

The actual telescope is just the bare minimum you need to start stargazing. For a really full experience, you'll need various accessories. And if you thought buying the telescope was a huge investment, trust me, you're going to spend a lot more on the accessories! These are the various eyepieces and other optics I use - and a hairdryer! That's for clearing up any dew or frost on the objective lens during particularly cold nights. Never ever clean or even touch the optics on a lens with your bare fingers! 



Other equipment - GO-TO computer controller, camera, camera remote and cables, video cables, solar filter, USB computer connectors - and a good old fashioned compass to quickly find my way round directions ....



25mm and 32mm eyepieces - wide-view optics for looking at stars, star clusters, larger nebulae, splitting binaries and spotting your targets



6mm and 10mm eyepieces - for zooming and seeing more detail, such as planets and the moon surface. What you gain in magnification, you will lose in terms of brightness though.



A 2X Barlow lens, which you attach in front of your eyepiece - it increases the magnification of your image by two times.




Filters, which you attach to the front of the eyepiece. The coloured ones at the top are used to highlight faint features on planets; the ones at the bottom are for reducing glare, 'fringing', block U and IR light and produce spectra for analysis



My Olympus Camedia C-4040. It's old and cheap. But does everything I need for an astronomical camera - compatible attachments to eyepieces, remote control operation, user-defined zooms and exposure times, etc.



A Celestron Neximage CCD imager - basically a webcam for astronomical purposes. The imager takes videos and has a magnification equivalent to a 6mm eyepiece. But using the reducer lens at the bottom can extend its field of view.



The AutoStar controller for controlling the telescope's GO-TO computer.




The Back-of the-Garden Astronomer's Guide

Meet my telescope and best friend. The Meade ETX-80 is 80mm (3.1") refracting type telescope with a focal length of 400mm (f/5). Tiny by most standards but good enough to see Jupiter's moons and Saturn's rings. It has an internal flip function Barlow lens to increase the magnification of the eyepiece in use, and an internal flip mirror for mounting optics at the rear of the telescope. Also comes with the Meade AutoStar computer controller handset, which automatically guides your telescope. Bought online from Harrison Telescopes for the princely sum of £289.




The bear essentials ......



 


Make sure you are well-prepared for your night out - here are some fashion tips for the amateur stargazer!





A standard visual observing setup - a 25mm eyepiece at the bottom for wide field views and spotting, a 10mm eyepiece and Barlow lens at the top for zooming in on the action.




A close-up of the eyepieces. That big knob next to the eyepiece at the top is the telescopes focuser.



Using special attachments, you can attach a camera to the eyepiece. Make sure you connect your camera to a remote control or laptop to take pictures, zoom or change exposure settings. At high magnifications, touching the camera even slightly will make you lose your target image on the scope.




You can even completely do away with the eyepiece and just use your telescope as a guided camera mount - especially for wide view shots of constellations. Just use the lower wide view eyepiece to locate the target constellation and take your picture!  




Stargazing isn't just restricted to night -time hours. There's one really big star you can't miss seeing during daylight hours - the Sun! You can attach a solar filter to view the sun and features such as sunspots - just as you would with a telescope at night. Never, ever, ever look at the sun through a telescope without solar filter - you'll fry your eyeballs out.