The Veil Nebula is a supernova remnant it’s distance is about 2400 light years from us. This nebula has some really interesting details and ´components in it.
Nights are getting more brighter and brighter… Eventually at the summer, the nights are too bright to do astrophotography because we have this thing here called midnight sun in the northern parts of our country.
This image is one of my favourite pictures of this year and I took it with my new IR-modded Canon EOs 700D (thanks to my friend Santeri who was willing to sell it). In the middle you can see NGC 4438, the Eyes Galaxies! In the next year I will be photographing it more.
Or more commonly ”Pacman Nebula”. This picture is a good example that you don’t need consume thousands of dollars/Euros only for the camera… to get decent images.
This has been taken with pretty modest and cheap gear:
Secondhand Atik 16Ic with motorised filterwheel costing 150 € for me, Omegon 12nm Narrowband filters 273 € with shipping. Most expensive was the 80mm Ed Apo scope and motorised HEQ-5 mount, but you could get them as secondhand gear costing around 500-800 € (together) here in Finland.
This image total exposure time was only 1h 15min, so it will get a lot more better when adding more exposure time!
Hey. It’ s been a while… I have been pretty busy lately, but I haven’t stopped astronomy hobbies/astrophotography etc.
Here is Mars from last night taken with ZWO ASI 120 MC-S and Celestron XLT C11 scope. Hope you like it!
Hi guys! This whole season has been quite interesting. I have decided to go more deeper in my astronomical pursuits and started to do more photometry. And I’m not alone in this… My friend, Juha is also enthusiastic to learn CCD-Photometry. Juha have a long experience in visual photometry, so it has been a great help to learn the basics of photometrical observations. There is also few other members in Porin Karhunvartijat, who wants to do more scientific observations, so we are going to have a good team!
Our plan is to start to do good quality observations of a cataclysmic variable stars and in some point exoplanet observations, with our local amateur astronomy associations (Porin Karhunvartijat) equipments! Porin Karhunvartijat has a observatory in Ulvila, Finland and we just got our new mount assembled in there (Losmandy G11). The scope which we are going to use is Celestron XLT C11 and our CCD-camera is SBIG ST 8300m.
So… When do we start? The answer is, that we have already started and the picture above is results of our first processed observation (13.2.2019) of a symbiotic variable star, called CH Cyg.
You can see more in URSA’s ”observationsystem”: taivaanvahti
Well lately I have been adjusting our club new Losmandy G11 mounts polar alignment, but I had to test a little bit how well it works. So I got this with Celestron XLT C11 (2800mm focal lenght, 15min, ISO1600) and Canon Eos 1000Da. It is made unguided 1min single exposures, 15 kpl/min in total.
Terve kaikille harrastajille! En ole suomeksi paljon blogissani kirjoitellutkaan. Viimeaikoina olen saanut kyselyitä uusilta harrastajilta ja huomasin, että apuja tarvitaan mm. pixinsightin käyttöön, joten päätin tehdä ns. pikaoppaan tähtikuvien pinoamiseen ja kalibrointiin (FLAT-kuvilla). Opuksen tarkoitus on siis alentaa Pixinsightin käyttökynnystä, loppujen lopuksi kyseinen ohjelma on melko yksinkertainen ja se tarjoaa tähtikuvaajalle riittävät työkalut kuvien käsittelyyn alusta loppuun. Toivottavasti opus kelpaa ja siitä on kaikille apua!
linkki ohjeeseen:
Got this image of the Mars with Celestron XLT C11, 2xbarlow and ZWO ASI120mc. Processed with PIPP, Autostakkert and wavelets in Registax6.
Seeing was pretty decent and there was a clear sky, so I managed to get some details visible!
Last time I was telling basic knowledge of telescope what you have to know. In this part we will continue with that.
Barlows and reducers
There is a factor in barlows/reducer for example 2x, 3x, 5x barlow, or in reducers it can be 0,8.
To know your telescope focal lenght you just multiply your telescope focal lenght with the number of your barlow/reducer. For example SW N 200/1000 Explorer BD telescopes focal lenght is 1000mm and we attach 2x barlow to it:
1000mm x 2= 2000mm, so the focal lenght is now 2000mm.
Eyepiece
With your eye pieces, you can easily change your magnification. There is lot of different eyepieces and some are better quality then the others. This is something what you have to know… Even with best quality telescope, you can destroy the image quality with a poor eye piece.
Magnification
You can calculate easily what is the magnification in your telescope with this:
Optical telescopes
So maybe this is the moment that you have all waiting for… I will first tell what kind of telescopes there are.
Refracting telescope (lens telescope)
Refracting telescopes uses lens as it’s objective. Because making the lenses are hard work, they normally are quite expensive if they are made well.
Mostly used refractors are achromatic and apochromatic refractors.
https://en.wikipedia.org/wiki/Refracting_telescope
Reflecting telescope (mirror telescopes)
Reflectors uses mirrors as their objective. Compared to lens telescope, reflectors are normally cheaper and larger. There are lot of different type of reflecting telescopes and they are quite popular also, among the amateur astronomers, because they are quite big compared to what they cost.
Example: The Newtonian telescope, The Cassegrain telescope, The Ritchey–Chrétien telescope.
https://en.wikipedia.org/wiki/Reflecting_telescope
Catadioptric telescopes
Catadioptric telescopes are combinations of refractors and reflectors.
There is Maksutov Cassegrain, Schmidt–Cassegrain, Argunov–Cassegrain, Klevtsov–Cassegrain telescope.
https://en.wikipedia.org/wiki/Catadioptric_system#Catadioptric_telescopes
Mount
I would say that mount is as important as the telescope. Mount is better to be solid, and sturdy! And in astrophotographiy it is even more important to have good equatorial mount with a tracking motors, then a telescope…
alt-az
Two-axis mount for supporting and rotating an instrument about two perpendicular axes (vertical and horizontal).
– Dobsonian
a simple alt-azimuth mount.
Equatorial
The equatorial mount has north-south polar axis tilted to be parallel to Earth’s polar axis, with this it is more easier to track sky movements.
What to buy?
If you are a complete beginner… My advice is: DON’T BUY ANYTHING YET! At this point you should consider to join your local astronomy club. Clubs normally have many people in it and they are willingly to give you help and advice. If it’s not possible to join club… Then join different astronomy forums/social media groups, where you can see what people are using to different objects, you will suprise what you can do with a normal dslr objective…
Clubs also offer telescopes for rent, to their members. And many members have telescopes of their own and you can go with other members to look sky with em in star partys etc.
The best way to start observing the night sky is just to go outside with a starmap and learning to know constellations… You can also to take your normal binoculars and see Jupiter and it’s 4 biggest Moons with it.
There are also many DSO to look at, with binoculars. Like: Plejadies, M27, M31, M13. Then you will have somekind of idea what you are going to see with an expensive telescope.
That’s all folks!
Lately I’ve been getting a lot of questions, about buying a telescope and next post (maybe two part), will enlighten this issue. There is couple common questions that people make often when they are buying a telescope:
1. What is the best telescope with affordable price?
2. I want to see nebulas and planets which is the best telescope for that?
I’m sorry to tell that the answer is not simple… You really can’t buy ”1 for all telescope”, with affordable price and many affordable telescopes are more toys then a real telescopes. There is few things to be considered and know, before you go to market and buy one.
First thing is to think what you are going to observe mostly. Are you into planets, or maybe deep sky objects? Deep sky object are quite faint, so they need good light cathering capacity and wide field of view (not all DSO need wide FOV). And planets on their behalf, are mostly bright and small so, you would need longer focal lenght to get bigger magnification to see them better. On the other hand if your telescope objective diameter is small, you can’t use big magnifications, because the object will become blurry and then you won’t be able to see anything clearly. This kind of thinking will give you some ideas what to look for.
Second thing is to think do you need to move your equipment and how much you are ready to move around. Big aperture and long focal lenght telescopes, normally are quite heavy and sometimes it is hard to move around, all your equipments to your observing site.
So what aperture and focal lenght?
Aperture
- Aperture basically is the diameter of telescope and it tells you the lens/mirror size.
- Bigger the diameter is, the better the light cathering capacity is.
Focal lenght
- Focal lenght is distance of the image plane, from the lens/mirror.
- Long focal lenght gives you bigger magnifications and smaller field of view, when small focal lenght gives you wider field of view, but smaller magnifications.
f-Ratio
- Together these tell you telescope f-ratio… ” The f-number”.
- you can calculate your telescope f-number with a simple equation:
for example Skywatcher N 200/1000 Explorer BD has 1000mm focal lenght and 200mm aperture mirror, so:
- the lower this f-number is, the ”faster” the telescope can gather light. f5 and smaller f-number telescopes are considered to be ”fast telescopes”.
Barlows and reducers
Basically with these you can adjust the focal lenght of your telescope. Barlows will increase the focal lenght and reducers decrease the focal lenght.
Eventually I didn’t give you any recommendations of any telescope, but don’t worry we will come to that part… Maybe in next chapter?