Questions tagged [telescope]

Questions related to the physical instruments for astronomical observations.

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3
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1answer
135 views

What I can observe with a 80/900 refractor telescope? What can I study?

Recently I bought a telescope after a very good conversation with an astronomer friend of mine. The main goal is to see planets. However, Mars is so difficult and is far to find it in opposition. I ...
4
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1answer
113 views

How can a galaxy in-between our view and the galaxy behind it have a 'lensing effect'?

In this article, the author writes: This galaxy is so distant that it would have been invisible without the gravitational lensing effects of a large galaxy cluster called Abell 1689, located nearly ...
3
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1answer
624 views

How does making a refracting telescope very long reduce the chromatic aberration of an uncorrected lens?

Below are two cropped views of "Johannes Hevelius's 8 inch telescope with an open work wood and wire "tube" that had a focal length of 150 feet to limit chromatic aberration." from Harvard University, ...
4
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2answers
15k views

What can we expect to see with a telescope with a 70mm aperture and a 10mm eyepiece?

We purchased my young daughter a beginner telescope for Christmas and she's super excited to look at the large planets. Our telescope has a 70mm aperture and two eye pieces (10mm and 20mm) How much, ...
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2answers
4k views

Which eyepieces I can use it for best viewing experience using my existing telescope?

Telescope: Orion 09843 SpaceProbe 3,3 inch aperture(76mm), 700mm focal length, eyepieces - 25mm and 10mm focal lengths Hi, I am very happy and excited to see moon craters, Jupiter and Saturn. And ...
2
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0answers
63 views

What is the cost and benefit of building two identical telescopes?

I suppose that (especially space) telescope costs is dominated by design and development, not by material and manufacturing. So once a telescope has been developed and designed, how much extra would ...
2
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2answers
116 views

Source of mirror reflectivity data

I am trying to find a source of mirror reflectivity versus wavelength for the typical protected overcoat Aluminum mirrors used in astronomy. I need this to cover the whole visible range (300-1200nm) ...
3
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2answers
2k views

What's the useful magnification for a scope with 70mm objective lens?

Some of the spotting scopes which are e.g. 70mm claim to magnify terrestrial objects at 75x. But yet they cannot produce sharp and clear images at even 30x-35x. While 90mm scopes can do a better job ...
7
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4answers
348 views

Where exactly is the modification that first corrected the spherical aberration in Hubble's primary mirror?

The April 2015 CBS News article How NASA fixed Hubble's flawed vision - and reputation describes the modification taken to the Hubble Space Telescopes by the Space Shuttle that was used to correct for ...
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0answers
38 views

Combining lenses to make a telescope

Hi I have two Galileo 700mm x 60mm Astro/Terrestrial Refractor Telescopes. Can I take the lenses out and make one powerful telescope?
4
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2answers
250 views

VLT interferometry vs E-ELT?

If the VLT (very large telescope) can use interferomerty to act as a 200 meter mirror, then why are they trying to build the 39 meter E-ELT? What advantage does the E-ELT have, if the VLT can act as a ...
6
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5answers
16k views

Can an astronomical telescope view objects on Earth?

I am new to telescopes and I'm planning to buy an astronomical telescope like the "Celestron AstroMaster 114 EQ Reflector". Just curious to know whether it can be used to view objects on Earth (e.g. ...
6
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1answer
284 views

If we had the right technology could we see a distant star in detail?

If, for instance, Hubble's camera was a 10^300 times better could it see a distant star in details or is there a limit to the amount of light that reaches the earth's orbit or perhaps does the light ...
2
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1answer
57 views

What are some formulas that are associated with the Schmidt corrector?

I want to fully understand how an SCT works. Thus, I figured out I can use some formulas that describe how an incident ray that is parallel with the axis would act after refracting off a Schmidt plate....
0
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1answer
415 views

76mm reflector vs 70mm refractor? Both are at sale at $200

I'm starting my astronomy hobby and looking for a beginner telescopes to start with. I've searched couple websites and found these 2 within my budget. I know for a fact that refractors gives you ...
2
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2answers
358 views

What are the aberrations of an SCT? And how can they be eliminated?

The Schmidt-Cassegrain telescope is amazing! It is compact, suitable for astrophotography ,and it requires little to no collimation. However, the SCT has some inherent optical issues. What are they? ...
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3answers
83 views

Seeking advice regarding buying a telescope

I'd like to buy a telescope with a focal length of 700mm and an aperture of 60mm. Would I be able to use a telescope of this power to study the closer planets (for example Mars and Venus) and ...
8
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4answers
1k views

Can we see the color of nebulae?

Someone asked me this question: To see the color of the Great Nebula in Orion, how large the aperture of the telescope should be. I don’t even know whether this is possible. I understand that the ...
1
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1answer
116 views

Why aren't corrector plates aligned with the center of curvature in an SCT?

According to wikipedia, Schmidt corrector plates must be aligned with the center of curvature to eliminate the spherical aberration. However, in compact SCT designs by Celestron and Meade, that is ...
3
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3answers
300 views

Advice on first Telescope (refractor vs reflector), Barlow lens

I am planning on buying my first telescope. I am getting an 80mm refractor and a 114mm reflector for the same price range. Which would be a better option? Further, would a Barlow lens solve the ...
2
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1answer
83 views

Locate planets and stars for beginners

I am a beginner in astronomy. In fact, I just bought my first refractor telescope with 60 mm aperture and 600 focal lengths with 4mm, 12.5mm and 20 mm eyepiece and 3x barlow. Could I get info on ...
2
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2answers
87 views

How to see Comet 46P/Wirtanen?

I've got a Celestron Astromaster 114 telescope. I live in Los Angeles and would like to get a look at 46P/Wirtanen. Can anyone tell me when this comet is going to brightest and how best to locate it ...
5
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6answers
2k views

Would a telescope that uses Fresnel lenses be more practical than using regular lenses?

If we were to make telescopes with Fresnel lenses instead of regular lenses, would it be more practical? Would this also allow for much bigger telescopes to be made? Here is an example of the type ...
4
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3answers
942 views

Claim that 30-m class telescopes will have resolution far superior to Hubble: true?

This article makes the claim that the Giant Magellan Telescope (GMT, number 4 in the list) will have resolution 10 times better than that of Hubble, while the Thirty Meter Telescope (TMT, number 3 in ...
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0answers
128 views

Celestron NexStar 130 SLT Computerized Telescope GoTo Not Accurate

I am trying to use a Celestron NexStar 130 SLT Computerized Telescope, but I am not able to use the GoTo function. I do the three start alignment, it confirms matches, I make sure the level is ...
3
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1answer
241 views

How does this telescope work, and what is it for?

Procrastinating, I clicked on a suggested video (How Large Can a Telescope Be?) and after about 01:20 I saw a clip of a telescope shown below. I was confused as I ...
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1answer
440 views

Can't see any detail on planets with my new Celestron NexStar 130 SLT Computerized Telescope [duplicate]

Mars looks like a small white blob/circle and the same with all other planets. This is very frustrating. I've looked all over for a solution jumping from site to site and nothing. Please be different ...
5
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2answers
1k views

Why can’t I see any detail on planets?

I really want to know why I can’t see detail on planets. This summer my Dad and I went on a trip to Utah I went outside to look at the planets and couldn’t see detail on Mars, Saturn, and Jupiter. ...
2
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2answers
803 views

How to adapt small Dobsonian to use with a tripod?

I am the owner of a small 4", f/6.3 tabletop Dobsonian telescope with a 102mm aperture and 640mm focal length. It is based on a Dobsonian mount but I would like to use a tripod instead because of ...
4
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2answers
76 views

Question about the relevant physical parameters to build a backyard observatory

I live in a big city: São Paulo, Brazil. I would like to build a simple telescope dome to do some amateur sky obseravtions. But the whole project lies on the viability to see something interresting ...
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2answers
625 views

What are the advantages of refractor telescopes over reflector telescopes?

I've been thinking about getting a new telescope. From what I've read online, reflector telescopes are newer and better then refractor telescopes. Is there any reason to get a refractor telescope ...
4
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4answers
1k views

Mars looks like a blur

I took my telescope out tonight (I am new, just got the telescope a few days ago, it's my first one) and I was observing Mars, however all I see is just an bright orange circle, with no surface detail,...
11
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2answers
213 views

After Oumuamua passage, has an “urgency” telescope time request procedure been set up?

During the rapid passing of ʻOumuamua through our solar system, it was difficult to get instant telescope time. Usually, formal requests and a review process are necessary before telescope time is ...
2
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2answers
166 views

Why do we use filters in telescopes for astronomical imaging?

I have read that if we image without a filter we get no information about the color or SED of objects. Can anyone elaborate the reasons for using filters for imaging/photometry? What happens if we ...
0
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1answer
240 views

what can i see using celestron nexstar 127SLT [closed]

I am planning to buy celestron nexstar 127SLT and I want to know what can I see using my telescope.
0
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1answer
199 views

Type of telescope on Star Trek

In the first episode of Star Trek: Discovery, we learn that Captain Georgiou has an old-fashioned telescope in her ready room. Michael Burnham inherits it a bit later in the season. I wonder if anyone ...
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2answers
114 views

Help new Dobsonian owner

I need a bit of advice. I purchased a Orion xt8 and a lens kit with a 2x Barlow 6mm 20 mm eyepieces and every time I try pulling things into focus / magnification or focus goes out the window recently ...
3
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1answer
103 views

How do ground-based telescopes deal with earthquakes?

Astronomical telescopes observe particular points in the sky for hours or even days, and they have to remain particularly steady for the duration of the observation, as far as I know. What happens ...
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1answer
149 views

Looking at ourselves with a powerful telescope?

Could a small curved mirror and/or lens in Earth's orbit be aimed at a different hemisphere from where you are be be viewed with a powerful telescope to see the ground through the mirror? Would a more ...
3
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1answer
108 views

How to understand Kepler telescope under large aspherical wavefront

To my understanding, a Kepler telescope is designed to conjugate one plane to another. For example scale down/up the incoming wavefront onto a wavefront sensor for measurement. It works well for small ...
0
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3answers
568 views

Reflector vs refractor in terms of magnification, which one wins?

I'm thinking about getting a telescope and i'm debating between these 2 telescopes: meade and orion. Theyre both the same price so this question is not about the money, but about getting the most out ...
2
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1answer
88 views

Finding Jupiter, Saturn

I have a Dobson Omegon with a 640mm focal length and a 102mm aperture. My finderscope is broken but I can do without. I have located the planets with the naked eye but I do I do not see them through ...
1
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2answers
333 views

CCD in telescopes: Observation and Astro-photography

This is a Celestron CPC 800 XLT telescope. It doesn't seem to have charge-coupled device (CCD) attached. Can a CCD be attached separately to this 8" Schmidt-Cassegrain telescope even if it didn't come ...
2
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1answer
108 views

Array of telescopes with single orbiting collector?

Might such a thing give better images than we could get from other virtual telescopes with multiple collectors? Or is having multiple collectors not a limiting factor? Could a single collector ...
1
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5answers
426 views

Edu-Science telescope

I don't know much about astronomy, but my kids are asking for telescopes to view planets, stars etc. Could anyone tell me if this Eduscience telescope is any good? This kit contains a 40x with a ...
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2answers
585 views

What magnification is required to see detail on Mars / other local bodies?

I have a 125mm Jones Bird newtonian telescope (very shoddy) with 6x lens (2× + 3×) essentially we were able to see a very small O (yeah that's to scale) with varied shades of red. Is Mars far away ...
1
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1answer
662 views

Is the Celestron astromaster 130 EQ Model able to see nebulas and galaxies?

Is the Celestron astromaster 130 EQ Model able to see nebulas and galaxies? If this telescope is not able to see nebulae, please suggest me the best one telescopes for nebulas.
1
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1answer
69 views

Is it possible to see an image with radio telescope of something not so far away in detail?

Can an image of a person using a radio telescope see a person from far away? Could a radio telescope be made to see someone walking on Mars? https://space.stackexchange.com/questions/30477/could-we-...
1
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2answers
119 views

Amateur observing

I'm new to this could someone tell me if I'd be able to see planets with the Celestron Cometron FirstScope described as below on argos.co.uk: A compact, easy to use and powerful 76mm reflector ...
2
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2answers
260 views

Struggling to use my new telescope

I recently got my first telescope, a Bushnell reflector telescope. I spent a good while setting up my alignment. And I can see the moon perfectly! I went to look at another, Mars. I got it aligned in ...

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