Telescope Definition and 517 Threads

So, I recently finished my refractor telescope. I have a objective lens of 80mm and focal length of 900mm, 70mm focuser, tube length is 99.8 cm. I have a 25mm and 9mm eyepiece. I have been testing it out during the day time, on objects I can easily spot. First I use no eyepiece to focus on an...

Assume we drill a hole through the Earth - through the center towards the other side. Then we use a telescope, point it through the hole and observe stars on the other side of the earth. The telescope experiences a constant acceleration from Earth's gravitation. Accelerated movements have an...

I'm trying to make a handmade telescope, but I'm stuck with the lenses I bought 2 lenses. they are the same "convex from one side and concave from the other side" like glasses lenses. then I knew that I need a double convex for both the object lens and the eyepiece lens. so I decided to put the...

Hi Me and a couple of class mates are working on our bachelor's project of which the mission is to measure the temperature of the sun using a parabolic antenna. We are having great troubles trying to come up with an equation relating the antenna temperature (which we are able to calculate with...

Complete reflector novice here. Just got a reflector (using refractor before). I had no problems doing astrophotography with my refractor however with the reflector I get double images. Why is this so? Is this a collmination problem? It's not the camera because there's double images when I...

Just noticed the Kepler telescope is running in "safe mode" burning precious fuel very quickly. Could be the end of the show for K-2 if they don't come up with a workaround soon. If anyone hears of progress regarding the problem could they please mention it here? Thanks:smile...

Would such a telescope be useful for discovering new main belt asteroids: http://www.officinastellare.com/products_scheda.php?idProd=29

What was the diameter of the telescope that Charles Messier used to make the Messier Catalog?

I want to build a telescope and want to know which type of lense is better suit for this. Please anyone help...

What are the different formulas for the calculation of magnifying power of a microscope and a telescope? And how would we use the sign conventions in them?

Hi all, first-time poster here excited to get my first telescope working. The issue: I see the silhouette of the secondary mirror and spider vanes in front of everything I focus on! I read through a similar post here a few years back, but the solution didn't work for me. Details: 6"...

I've been reading about stellar aberration and was particularly drawn to the experiment where two telescopes are tracking a star but one is filled with water to slow the speed of light down. The results of the experiment show both telescopes to be tilted to exactly the same angle which...

Homework Statement Find the magnification of a 10" reflecting telescope with a focal length of 1250mm and a 250mm eyepiece. Homework Equations 1/f=1/do+1/di M=hi/ho=-di/do The Attempt at a Solution Not really sure where to start. If you could, please explain how you got the answer. Thanks for...

Hi my question is about how the brightness of stellar objects is effected when we look at them through a telescope. Firstly when I looked through a telescope I noticed there were more stars I could see. Is the reason because a telescope can gather more light than our eye or does it have...

cool article on the progress of the JWST constructionhttp://www.space.com/31838-james-webb-space-telescope-mirror-assembled.html?cmpid=NL_SP_weekly_2016-2-05Dave

Having the unaided eye's pupil to be 6.4mm and the diameter of a telescope 8-inches, how can I calculate the amount of light the a scope collects over the human eye?

Does JWST has any significance in fundamental physics research? What kind of questions would we get answers to?

Homework Statement Soon astronomers will be imaging the “shadow” of light from the event horizons of black holes. Since black holes are very small, this achievement seems impossible. Nevertheless, it is possible for three reasons: 1. Supermassive black holes have large event horizons. 2. Radio...

Hello pf, I have been trying to grasp the concept of RA. I have read through a few books and I know that it is measured eastwards from the point on the celestial sphere where the Sun crosses the celestial equator at the vernal equinox. I just want to check I understand this correctly. Does it...

Hi Guys, I studied physics for my bachelor but still I am not a super expert, although I am still working closely to physics (but not so much astronomy). I was wondering if it would be possible to build a radio, or some other devise (any ideas?) that could be tuned at the frequency where the...

Is it possible to rig a Truss Dobsonian telescope like this one so that you can control it remotely from inside of a building while the telescope itself is on the roof of the building? Then is it possible to attach some sort of adapter to the telescope that would allow you to hook up a camera...

I bought the celestron firstscope about 4 to 5 months ago.in the beginning I was pretty excited and enthusiastic but as time wore on,I found myself away from the scope.now I want to restart astronomy but I would like some tips to make it more fun and interesting so that my scope don't end up...

To increase the resolution of an instrument, smaller wavelength and larger aperture is desirable. It is mentioned in some textbooks that the "effective" diameter of a telescope can be increased by using arrays of smaller telescopes. I just wonder why it is possible because every telescope is...

Over the last year or so I've been thinking seriously about getting a telescope, having my eye on the Celestron Nexstar 6SE model or getting a slightly smaller 5" model that's more automated for about the same price. Well, yesterday my mind got made up for me as it was my birthday & my wife...

Hi guys! I have a Levenhuk telescope and still have a question what is the best way to clean the mirror? Thanx for the help.

http://www.askamathematician.com/2013/04/q-what-kind-of-telescope-would-be-needed-to-see-a-person-on-a-planet-in-a-different-solar-system My speculative question on the subject is in the sphere of Einstein General relativity applying to the problem. So we all now know that when light passes...

Can anyone please provide some web links or tips for making a homemade reflecting telescopes by own?

Lets suppose I had a very powerful telescope and I could see 10 light years away. Would I see cars and people on that planet as they were 10 years ago? Would I actually see the people moving and the cars moving on the ground?

hello , any one give me an information that how i make my own 8" telescope...And for making telescope which instuments are require

It sounds silly to ask such question or stumble in such problem, indeed! But I was willing to make some small telescopes for young friends of mine, to encourage them to delve in the skies. So, I bought: 1. Double concave, spherical glass lens, with a focal length of approx. -75mm and diameter...

I've been to a starparty and realized my telescope is well underpowered and for what I want to view. My budget is £500-£600 and I was looking for something with a ten inch aperture. I was looking at the Orion xt10 classical with barlow set or the Skywatcher skyliner 250px dobsonian. Could...

1st tope, in my sci-fi universe let's say there is a warp drive that can power a ship that can travel 10*c. One of the first things I have people doing is coming up what is called "The Big Picture Project" which is installing this drive onto probes and sending them out unmanned and have it so...

A awhile ago I wrote a program to calculate various things like maximum resolving power of a given telescope's primary mirror, angular diameter of an object of a given size from a given distance and mirror diameter required to see an object of a given angular diameter. However, I seem to have...

why is there no telescope like Hubble on the international space station/? as i know, the iss is only 150 km lower in orbit than the Hubble space telescope, and is at different inclination. Having people around is pretty convenient i think, so replacing parts and doing regular maintenance would...

Hey guys! My dad bought me a reflector telescope (Levenhuk Strike 120 plus) but I am having a hard time figuring out how it works. I managed to assemble the telescope with the help of my dad but we cannot seem to see anything through it. Any suggestions what could possibly be wrong with it? Or...

I am going to make a Dobsonian telescope. Primarily a 6" f/8. I have no idea what the secondary mirror size would be an its distance from the centre of the primary. I have been told that if the secondary is too small then the effective aperture would be reduced. And i do not understancd these...

I'm just a bridge engineer and amateur astronomer, so I'm hoping someone here with more advanced expertise in light waves and reflective surfaces can help me. Basically I was wondering how big a space telescope's primary mirror would have to be in order to view an exoplanet 10 or so light years...

I have been looking at these diagrams: From the following link http://www.astronomynotes.com/telescop/s3.htm And I just can't seem to figure out why the first telescope design doesn't show a shadow and in the second why the presence of the secondary mirror, and the hole, do not affect the...

I am slightly confused about what the term 'astronomical telescope' covers. My textbook seems to be implying that astronomical telescopes are refracting telescopes with an objective and eyepiece lens, and reflecting telescopes are separate to astronomical telescopes. On the other hand I have...

I don't quite understand the concept of field of view of a telescope... Specifically, I am trying to understand the advantages of reflecting and refracting telescopes compared with the other, and my textbook says that "Refracting telescopes have a wider field of view than reflectors of the same...

Hello! I am learning about refracting telescopes and am slightly confused. I have read that a refracting telescope will magnify planets, but not change their brightness, but will not magnify stars as these will remain as point objects. It just makes the stars appear brighter. I am slightly...

Well I was watching this documentary.there was reference to laser telescope.it use laser to get images of universe.I know the basic principle.it shoots out laser is space and get images from reflected light.but is that lasers really powerful enough to get images of objects which are far in the...

Homework Statement See the image I uploaded. Homework Equations Paraxial approximations The Attempt at a Solution I think the image is formed after the ocular, and I understand the system is afocal. The magnification is also less than 1, but the angular magnification is >1. What I am stuck...

Homework Statement An optical telescope has a diameter of 1.5m. It is placed at a site with 'seeing' of 1.0''. What is the expected resolution in arcseconds from observations made with the telescope at 1000nm? Give your answer to one decimal placeHomework Equations Theta (rads) = 1.22 *...

So basically, in the text below, they say that maximum angular magnification is achieved when the object is placed 25 cm from the eye, i.e. at the near point. The minimum angular magnification is achieved when the object is placed at the focal length. However, for the chapter on the telescope...

I run an astronomy club at my school, and I recently discovered that the robotics club gets $2000 from the school every year to build a robot. They then go on to compete in tournaments with that robot, so that justifies the $2000. It would be great if I could get the school to give us $2000 to...

What are the best telescopes for amateur astronomy? I realize that there are many differences between telescopes, but let's face it. If I'm going to invest in a great telescope, I want it to produce a high-resolution image and to survive for a significant amount of time. -- and I absolutely do...

Hello! I'm a first year undergrad student and I have the oportunity to do research durring summer with an Ritchey–Chrétien 400 mm telescope. Can you guys recommand me something to research? I don't even know where to start with my search for interesting topics that are not too hard and that will...

I was wondering if anyone would help me get my hands on some telescope data and images of exoplanets. I know they must exist somewhere in databases on the internet, but I haven't been able to find them myself. It would be great if one of you could show me where I could get them or even if you...

The Wikipedia definition of angular resolution is 'Angular resolution, or spatial resolution, describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major...