OASA Offical Guide
Astronomical projects to do with a Small Telescope
If you are reading this then congratulations! you have bought a new telescope to explore the heavens! In this short guide we are going to look at some of the exciting things we can see in the night sky and even some, during the day
Warning: never look at the Sun directly with any telescope or optical device unless othewise instructed. It can lead to instant blindness
Projects The Moon Jupiter Saturn Observing the Sun, safely Some popular Deep Sky Objects
You would not associate anything much happening in the night sky. When you gaze up from one night to the next or over the course of a few hours you could be forgiven for thinking, whats the point, nothing changes. The stars all move across the sky as the Earth rotates but the stars never change position This is far from the truth. Planets for one move through the night sky as they orbit the Sun. The Moon changes phase as its orbits the Earth you would not know it but some planets have their own moons which orbit them. Like Mars, Jupiter, and Saturn to name a few. We are going to look shorly at some of jupiters Moon’s.
Image of Jupiter ta the author using a webcam
Jupiters Moons Jupiter is the largest Planet in the solar system and has at least 63 known moons. 4 of these are visible through large binoculars or a small telescope. They are Europa, Io, Ganymede, and Callisto.
aken by
There are several exciting things to note with these moons. a) We can see them move in realtime during the course of any evening b) They tend to move (transit) across the disc of Jupiter. Many people enjoy imaging Jupiter during the course of a night using a webcam (details on that in the OASA courses you are signed up to). It only takes a few hours before you start seeing the moons move as they orbit Jupiter. If you have a powerful enough telescope you might even see the details of Jupiter as well. like the great red spot which will also move across the planets surface during the course of the night. Sky and telescope app
Project suggestions Why not observe Jupiter over a few hours and make a sketch of the positions of the moons see how they change Can you name them? Check out this link to see how Do you see the small belts of Jupiter? Study closely, can you see any features, watch too as these move across the surface as the night moves on
Saturn Even though it is very hard to see the moons of Saturn, it is possible to see the rings with even the smaller of telescopes. Saturns rings themselves are divided into 5 rings we can see, A, B, C, D, and E sections But did you know these were actually themselves made up of hundreds of 1000’s of tiny ringlers. Dare i say it too they are only about 4km thick!
Moon You could not talk about things visible in the night sky without talking about the Moon. We often see the Moon in the night sky usually with the right side illuminated. As the nights progress (and weather allows) we see the illuminated size stretching across the lunar surface We say the Moon is “Waxing”
With each phase there is more to see as the Sun’s rays light up different parts of the Moon from one night to the other Did you know a) Each part of the moon spends two weeks in daylight and 2 weeks in darkness b) because of the nature of the way the moon orbits the Earth in relation to the Sun we NEVER see the same detail on the Moon even for identical phases. You will need to wait 25 years to see the same detail again
imagew credit http://apod.nasa.gov/apod/ap110409.html
Lunar Landing Sites
image credit : http://www.bobthealien.co.uk/moonmap.htm
It can be fun to see if you can spot some of these with the naked eye
Suggested Projects There are a number of exciting things we can do with the Moon. a) See if you can sketch some detail on the Moon, choose a prominent crater. Sketch it if you can from one night to the other, see how the detail changes with each phase b) See if you can make a rough sketch of the Moon at each phase, can you collect the entire lunar calendar? Each phase from new to Full? Do you have a webcam? Why not see if you can image a section of the Moon and process it. Do the same for the same section over the course of a few days to see how the phases changes. There are also some great craters and regions you can image. like Copernicus Tycho Clauvius Appennines Got a reasonably stable mount? Why not make a Mosaic of the Moon? Takes time and patience but you might have a nice enough image to print for th wall! This primer shows how!
Clauvius Credit: https://themoon.wikispaces.com/ Clavius
Image credit for lunar shots top right and bottom ritght Alastaitr Leith
Clavius is one of the largest crater formations on the Moon, and it is the third largest crater on the visible near side. It is located in the rugged southern highlands of the Moon, to the south of the prominent ray crater Tycho. More can be read on Clauvius here
Tycho - even visible through binoculars
You can see the ray structures coming from it Credit http://www.sfu.ca/geog/geog351fall05/ group3/Tycho.htm
Tycho. named after Dutch Astronomer, Tycho Brahe, is a reasonably young crater on the Moon. Located in the south highlands of the Moon. More information on the crater is available here
Copernicus
Apennine Region
All the craters and regions in this guide are visible with a small to medium telescope. The list is far from exhaustive but does give the learner some bearings to get started. The Moon is always an interest to observe, in fact it was the first object the author observed through a telescope! The great thing about the Moon is the dark sea areas (called Mare) are visible with the naked eye but it takes a pair of binoculars or a small telescope to really bring out the majesty of the craters. The Full moon is probably the worse time to see these, better observed during half moon or in this case Gibbous
Some images of the Moon taken by the Author
Cresecent Moon
Each of the the Authors DSLR Cam Waxing gibbous
Full Moon
ese were taken with s telescope and a mera.
First Quarter (half Moon
Mars and Venus It is no mistake i have left these til later in the guide. Although both objects present a decent view through the telescope they are not what i would call easy objects for small telescopes.
Venus being closer to the Sun tends to set reasonably early in the evening. The planet is about the same size of the earth. It is not easy to see any detail on the planet (such as clouds) and larger telescopes would be needed with special filters to resolve it. However it MIGHT be possible for the keen eyed to see the phases of Venus.
Credit; Pioneer Image of Venus Orbiter
Mars Mars is never out of the news for the speculation of life, again though it does present a challenge as its a small planet. Making it difficult at the best of times to see any detail on the planet. The red colour is due to iron deposits but we can also see the dark areas. It is possible to resolve with a small telescope. I have done so with a 60mm refractor. Below is a recent image i took of the planet.
Taken with the authors 8 inch telescope using a webcam. Mars was at close approach when this was taken.
Deep Sky Objects Despite what we say about the larger the telescope the more we can see, many small telescopes will allow you to see The Great Orion Nebula, M42
A bit about colours Our eyes are no sensitive enough to the colours of nany deep sky objects. We see things in colour during the day a light falls on the inner cone area of the eye. Our pupils also close up a little to moderate the amount of light coming in But when it gets dark, the pupils will dilate to allow more light to enter the eye. As such a lot of light then falls onto the rods of the eye which only detect black and white. They are more sensitive than the colour cones of the eye which cannot detect colour in light that faint For this reason too you will need to use peripheral vision (to make use of the rods) in order to get a better view of the object, like the Orion Nebula. This is hard for some people so if you stick a rubber on the end of a pencil and gently tap the telescope with it this should help.
M45 Pleaides These are an open cluster and visible in the automn / winter night sky in the constellation of Taurus. (top right from Orion A test for soldiers who wanted to join the Roman Army used to be to able to count the number of stars in the cluster. Other ancient regiments used it to select archers
M31 Andromeda Spiral In the constellation of Andromeda, the galaxy is 2.25 million light years away and one of our closer neighbours. Binoculars and small telescopes show it as a smudge. Larger telescopes will show stucture. Visible all year round
M33 Sprial Galaxy The M33 Spiral galaxy is one of our closer neighbours, its a face on galaxy. While M31 should be pretty easy to spot (even doable in light polluted skies) M33 might need darker skies, but if you have that then binoculars will show it as a faint smudge Visible all year
M51 Sprial Galaxy The M51 is another of our own closer neightbours and a favourite of Astrophotographers in that its also a bright galaxy to capture. Even in moderately light polluted skies a pair of binoculars will show it as a faint smudge. Small telescope will show it as a faint smudge but larger apertures start to show structure (10 inch and above) Visible pretty much all year round
M13 Hercules Globular Cluster This cluster visible in the constellation of Hercules is a nice summer object. Its a compact structure of ancient stars. There are many other examples like it (M92 is in the same constellation!). This is a good binocular object in moderate skies. A small telescope shows it as a smudge.
M15 Pegasus, Globular Cluster M15 is a nice globulsr cluster albeit, not as bright as others mentioned but a nice binocular object
Daylight Astronomy! Clearly, astronomy is largely a nightime persuit but there is astronomy we can do during the day. The Moon for example is frequently visible in the sky during the day and is always a delight to show children. The authors own are always pointing it out to their dad! It is also perfectly safe to put the telescope on it during the day (though care hould alwys be taken to avoid the sun) Which brings us onto our next and final topic Solar Astronomy The Sun is our nearest star and is the reason for our daylight and for all life on Earth. It is fascinating when you think that an object so far away can be responsible for daytime and for all life on Earth!
Also perhaps lesser known is the Sun is 93,000,000 miles away and it takes it light just over 8 1/2 minutes to reach us (so yes we would be looking at the Sun as it was that time back. So if anything happened to the Sun (suddenly) it would take that long for us to know about it The Sun also shines by converting Hydrogen to Helium which it does at its hot core (hot being an understatement its over 15 million degree’s Celcius in there!) The Suns surface is cooler at 6,000 C (your parents over heats at about 200 C so a massive difference. The point i am making is if you observe the Sun directly that heat will blind you The Moon wont as it only reflects the suns light not the heat This said there is a safe way to observe the Sun
Suns Spots Every so often the Sun starts to form dark areas which we call sunspots. They are where the magnetic field of the Sun has become tangled resulting in the area there cooling and producing a sun spot. If you have a pair of binoculars or a small telescope you can use these to project the Suns image onto a piece of paper where once focussed you can see Sun spots (this does NOT work for reflectors)
Caution I know i gave this warning at the beginning but here it is again, do NOT view the Sun directly with any telescope or even with the naked eye. You will surely damage your eyesite. Also as its human nature to use the finder to find things please remove this if using for solar astronomy. not only will a glance through even that likely blind you but there is a danger that someone could still get burned. If you cannot take it off, then put the dust cams on (both sides!).
Lighter area is called the penumbta Dark area is the Umbra
So using the shadow to align the suns rays through the telescope onto a piece of paper as you focus will begin to view Sun spots. A nice project is to sketch these and see how they change and move across the Suns surface from day to day.
So where next? This guide was written as an intro only, there are far more objects in the night sky visible to both your naked eyes and equipment. This guide is only to introduce a few and to get you going. I suggest purchasing a decent star atlas, one of the collins series would do. I would also suggest investing in a head torch (red) this will allow some light while outside while not effecting your eyes too much and leaving your hands free Bookwise i am always going to recommend Turn Left at Orions by Guy Consigmaglio. A book written for people with a small telescope which shows what objects are visible to small to moderate telescopes in the night sky with even sketches showing what to expect. Next step is get to a local astronomy society
Software There is a wealth of software freely available you can download Stellarium is a free open source planetarium program installs on most computers and shows the night sky the way it is live Image capture if you go that way SharpCap2 (for webcams) Registax (for webcams) Deep Sky Stacker (for DSLR) GiMP (for image processing) Photoshop is better if you have it
Note on “M” objects As a beginner you have likely been bombard with terms as M42, M13 (we’ve used them in here). But what does it mean? “M” is the designation of the Messier catatlouge which was compiled by Charles Messier. Charles Messier was a comet hunter who discovered comets. He grew tired of spotting fuzzies and watching them over and over to see if they moved. As such he developed the Messier Catalouge which is used to this day. Although it is hard to see how he could mistake the likes of M45 as a comet and M42 is even visible too to the naked eye. Another Catalogue in use which sadly we do not use often but still nevertheless is worth using is the Caldwell Catalougue. Developed and compiled by the late Sir Patrick Moore (yup the same who presented the Sky at Night). He noticed that Sir Charles Messier had left off a number of objects which he felt should have been included. So proceeded to compile a list of these which become the Caldwell Catalouge (well he could not be the “M” designation again).