Telescope Definition and 506 Threads

A while back, I posted here asking for telescope recommendations. After many members advised getting a dob, http://www.skywatcherusa.com/8-dobsonian-telescope-s11700.html" is what I went with. I love this scope. Seems very well put together and can capture some pretty amazing sights. One...

I'm a freshmen in college (currently undecided on my major) and am seriously considering an undergrad in physics with the intention of going to graduate school for astronomy. But before I get serious about it, and with Christmas on the way, I want to get a decent telescope. I'd say my possible...

Homework Statement I need to build a telescope from two magnifying lens, one is 2x the other is 5x. First I need to give the total magnification possible, state which lens to use as the objective and finally to state the length of the telescope. Homework Equations l Ml = Fo/Fe total...

hi, i don't understand why the 2 converging lens telescope's magnification is given by M = f_o / f_e where f_o = focal length of objective, and f_e = focal length of eyepiece... issn't M = image distance / object distance... in the case of a infinity object, the image is also infinity...

Hello! I'm not sure if this is the right section but it seems the best one for this question. I've been looking to buy a telescope just for fun and I'm surprised with just how many different options are available out there. I'm looking for something that's good for beginners since I've never...

Can I see anything other than the planets with a 4" telescope? I saw Jupiter (and four of its moons), Neptune, Mars and Venus but they were all really tiny so I was wondering if the planets are so tiny does that mean I wouldn't be able to see any of the other objects, like galaxies and nebulae...

Is anyone here familiar (more or less) with the new type of telescope called IACT, Imaging Air Cherenkov Telescope. Apparently TeV gammarays come to us from Active Galactic Nuclei (AGN) which are massive accreting black holes. Individual TeV photons leave blue or UV trails in the atmosphere...

Publicity often says that a new telescope can detect a candle across the Atlantic, etc. Well, a candlepower is defined as 1/683 Watts at 540 X 10^9Hz. This gives photon energy at 2.2 eV. One candlepower produces 4.2 x 10^15 photons/s radiated isotropically. At 3,000km the area of the...

Well I've decided to buy my first telescope and I've been searching craigslist for 'em. My price range is ~$200 and have so far found some (seemingly) good scopes. I've so far narrowed it down to three scopes, and I was wondering what you all thought about them. The scopes (all listed in...

I highly theoretical question, hope you guys can help. Say I have a telescope orbiting Earth at 100km, and say on the ground I have a mirror (of about 2x2m). Could the telescope see itself through the mirror (i.e look down to earth, zoom in plenty and see itself looking down). Thanks...

http://arxiv.org/PS_cache/arxiv/pdf/0908/0908.2696v1.pdf Abstract. Several early spyglasses are depicted in five paintings by Jan Brueghel the Elder completed between 1608 and 1625, as he was court painter of Archduke Albert VII of Habsburg. An optical tube that appears in the Extensive...

Planning is underway for the new super giant Magellan Telescope -- it will be the largest mirror ever on ground based telescopes, according to the link. http://www.gmto.org/

I have never owned a telescope before (only 20x80 binoculars) and I am looking to buy one now. I have 600 dollars to spend so i went and picked out what I THINK is a good good one for the price, however I'm not sure. So can any of you telescope experts out there take a look over this one? Also...

Hi I'm legally blind, so I own a small telescope that I use to see the board at school and stuff. On the front of it are these specifications: 6x16 0,25m-infinity 175/1000m 10degrees What do they mean? Thanks for your time.

I've searched for other topics about this on the forum, and the general advice seems to be that I should first try looking through telescopes at an astronomy club, talk to other amateurs, and buy binoculars to get familiar with the sky before I buy a telescope. There aren't any astronomy clubs...

So I just got my dads old telescope out, cleaned it, and installed new motors and cleaned the primary and secondary mirrors, and it's ready for use! It's a reflector with a 4-3/8" primary mirror, and I wonder: what can I see with this thing (besides the moon, obviously)? I know this is a super...

Homework Statement The Hubble Space Telescope is poered by two solar panels as shown. The body of the telescope has a mass of 11 Mg and a radii of gyration kx = 1.64m and ky = 3.85m, whereas the solar panels can be considered as thin plates, eac having a mass of 54 kg. due to an internal...

in a refracting telescope, the lens's diameter is 1.02 m and its focal length is 19.4 m. how long must the telescope be to get an image, 40 times bigger? i would also like to get a link to a site explaining this kind of elementary optics.

I'm putting together the Itty Bitty Radio Telescope. In the instructions (see: http://www.aoc.nrao.edu/epo/teachers/ittybitty/procedure.html), it says to use a .1Mhz RF Choke. I have been unable to locate this particular frequency, as the only one I have been able to locate has been a 1kHz RF...

Greetings- I'm new to PF, but I just wanted to ask about telescopes. I'm new to astronomy, and I am looking to buy a new telescope for under $400. I mainly have been doing astronomy with binoculars (16x50), and I believe that I want a telescope with a relatively wide viewing field and high...

Able to industry 6inch reflector telescope,but I found that the image of the edges of the mini-optical example, if I looked at the moon I saw three Oqmra This note I did not use the eyepiece My question is: Will this form reflector when not using the eyepiece? Thank you very much

It fell halfway over, denting my metal garbage can lid. The finderscope came off but I could easily reattach it. I can see light and blur now...what should I do?? I don't want to just open it up without knowing what I'm looking for. Thank you!

Minimum Resolution Angle Problem Homework Statement The radio telescope at Arecibo, Puerto Rico, has a reflecting spherical bowl of 295 m diameter. Radio signals can be received and emitted at various frequencies with appropriate antennae at the focal point of the reflecting bowl. At a...

how can i make a telescope eyepiece please help me !

I have a Bushnell 100mm Mak Cassegrain telescope. When viewing Saturn with my 32mm eyepiece I can see it but I can't differentiate between the rings. When I use a 4, 6, or 9mm eyepiece, the image jumps so much I give up. Why is that and what can I do? Thank you so much. penny

hello, I found a concave mirror telescope in my town I think that it is very good for making Newton telescope Estimated length of 20 cm I will make a telescope , but I have a problem , I do not know the place of the focus and the place of secondery mirror; after focus or before...

Arccording to Nasa, the Kepler telescope will be working for 3.5 years in orbit and during that time it will observe about 100000 stars looking for exoplanets. Howcome it can finish for that workload?

I want to make an astronomical telescope, can anybody help. I need specifications for the lenses.

[b]1. For a Lab I have set up a "galilean telescope" where the objective lens a convex lens with focal length about 20 cm (F) and a biconcave lens of unknown focal length. I placed the biconcave lens at about 15 cm away from the convex lens as the ocular (so closer than the focal point) and then...

What is a Hubble Space Telescope and how does it work?

Hello, I have a question regarding a Cassegrain style telescope (or any other "obscured" type telescope, for that matter). Can someone explain (in detail) why the small secondary mirror out in front of the large primary mirror does not cause some sort of a "blind spot" in the center if we...

Hi, I have just recently gotten a 8 inch dobsonian telescope. I have two lenses, a 9mm and a 30mm. I really enjoy going out and seeing the sky and I have a few questions to make my outings a little more successful. The way I focus the telescope is my adjusting how far out/in the eyepiece...

Im a Physics student at UNC-Charlotte. I just got my first telescope and I already have a problem. I can pinpoint a star and see it but it looks the same size as it does to the naked eye. I changed eyepieces and everything. Still just a tiny little dot. Does anyone know what could be wrong...

Which are the top telescopes producers ? i want names of company

Hi there, Could somebody explain how illumination - by which I mean flux per unit area - depends on the mirror diameter of a telescope and/or its focal length? Is this different for point objects like stars and for extended objects like nebulae? Thanks in advance, Nick :-)

Homework Statement An earth-based telescope with a mirror of diameter 2.4 m can record the im- age of a faint star in 1 hour. A telescope placed in space (above the atmosphere) has a mirror of the same focal length as that of the earth-based instrument, but its diameter is 1.2 m...

Problem: Centaurus A is 15 million light years away and a radio telescope can resolve structures of 1s of arc across. Show that the Structure is 75 light years across. Please Help!

Since i heard/researched about this Planet X (Nibiru), 2012 (end of days), Mayans (Sumerian), Annnunaki (aliens), revelations (bible) and all that, I want to start to look into our heavens! So, i wanted a good telescope that can see to at least pluto... Anyway, what does everyone think...

Hey all, I've been interested in the stars all my life and I know a bit about astrophysics from booklearning and what's been taught in school and whoud one day like to make a career out of it but I've never actually used a telescope before. A few weeks ago my parents saw me looking at some...

2 or 3 years ago we bought my father a telescope for his brithday, and ever since it has been a piece of 'art' in my house. I thought i'd put it to use, i have an interest in astronomy and now i really want to learn how to use this. the telescope is a Bushnell 675x5" Reflector Telescope...

Is a radio telescope less sensitive on the galactic plane? If so, why? /San

Can I use a shaving mirror on reflecting telescope as a primary mirror??

Hi. I am wondering what kind of light sources are used if one is using a fiber to do a single point source or artificial star calibration on a telescope? Any commercial ones can do if anyone knows one.

I've had a Meade DS 114 for a while. My kids dismantled it and apparently a piece is missing. The focuser tube is 2"; my eye pieces are 1.25" Meade says there was a piece which adapted the 1.25" eye pieces for use in the 2" hole (which also allowed for use of 2" eye pieces I guess). My...

...and it was INCREDIBLE! Here in Gilbert, AZ (basically on the outskirt of Phoenix) by the bird riparium there's a small observatory with a 16" telescope. We went up there and looked at Jupiter, Saturn, the moon, some stars, and the moons orbiting Jupiter and Saturn. I was stunned to actually...

Hi I had posted here for some advice a couple of months ago in the past, and it was very helpful. I have yet to buy a scope; however, I am on the presently on the verge and wanted a little more advice. I have basically come down to a decision that I will bet getting one of two dobsonian...

Hello, I'm looking to build my first telescope from http://www.apogeeinc.com/product.asp?itemid=766 (PDF file). My question is this, is this a suitable guide in doing so? If not what steps should i take to successfully complete this task?

So what do you guys think of this software? Do you use it often? Like it? Hate it? By some strange chance haven't heard of it or downloaded it? Here's a link to the website: http://www.worldwidetelescope.org/ I was astronomically challenged before using the software, but it's been...

Use Kepler’s laws to determine the period of the Hubble Space Telescope which orbits the Earth at an altitude of 610 km. I'm using the equation i know to find the period of an object revolving around another object T^2=Kr^3 T^2=(4pi^2/GM)*r^3 G=6.67 x 10^-11 M=5.98× 10^24 (Mass of...

Hi, I need to build a telescope for my physics class. I need to use any 3 lenses(converging or diverging) and 1 mirror. I was thinking of using an achromatic telescope design for that. However I am not sure what kind of lenses to use and whether I should make the eyepiece from two lenses or just...