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Questions tagged [telescope]

Questions related to the physical instruments for astronomical observations.

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How does the black hole at the center of M87 look like in the visible spectrum?

I learned here that the picture of the black hole we saw all over the news was a false color image, based on the radio spectrum emissions. How would the black hole at the center of M87 look like when ...
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What description of the image can we expect from the image of first black hole? [closed]

The EHT has published the first image of a black hole. I was wondering what could be the size of the original image of the first black hole and the format of the image captured?
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1answer
139 views

Event Horizon Telescope Data Cleanup

I was wondering how the researchers were able to minimize or neutralize confirmation bias regarding the data collected? As I understand it, the algorithm pruned much of the data, which would make ...
5
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1answer
160 views

Why not us interferometry to take a picture of Pluto?

Interferometry is among the best ways (if not, the best way!) to have an image of a very distant object. Recently a picture of the black hole at the center of M87 was released. It is the result of ...
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2answers
53 views

What to observe with a remote telescope close to sunrise time?

I have an access to a remote telescope at 05.15-05.45 am at Hawaii time. The sun rises at 06.15 am. I will use this telescope for educational purposes for high school students. I wonder 30 mins is ...
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1answer
213 views

Why did the Event Horizon Telescope take so long to take a photo of a black hole?

The Event Horizon Telescope is in the news now because they are about to release the first ever picture of a black hole. They have been working on this since 2006. Why did it take 13 years to produce ...
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National Geographic 76/700EQ telescope finder scope - help needed

I have this National Geographic 76/700EQ telescope I picked up at a second-hand store for $50. Anyone know how to adjust the finder scope on it? I turn the 2 pins on the top and side but it does not ...
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37 views

Within a given image of a multiple-image producing gravitational lens, does Fermat's principle apply?

The question Does gravitational lensing provide time evolution information? is excellent! When we see multiple images of the same object because of the phenomenon of gravitational lensing, do all ...
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3answers
171 views

Why does the Moon appear to be flat?

There's no way around it: when I look at the full moon at night it looks like a mostly flat disc, with at most a bit convexity in the middle. Phases of moon look like a full moon seen through a cut-...
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1answer
96 views

Angular diameter of the Sun's reflection from the ocean, seen from Sun-Earth L1?

I'm trying to understand how smooth the reflecting ocean surface would need to be to produce such a small bright spot as seen from the DSCOVR satellite at Sun-Earth L1. It appears to be only about 8E-...
3
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1answer
88 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 ...
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1answer
112 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, ...
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112 views

How did Johannes Hevelius' long telescope work? Why all the round holes?

The drawing below, found in Wikimedia and at lib.harvard.edu is of a very long tubed aerial telescope. I believe it is taken from his 1673 work Machinae coelestis. I've always wondered about the ...
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23 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?
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1answer
196 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 ...
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1answer
92 views

What soviet telescope is this?

A friend has a vintage telescope with a broken lens, I asked him to send me its catalog so I can see if I can buy him a new one, he gave me what looks like a Russian catalog, it seems a soviet ...
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1answer
88 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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1answer
39 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....
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2answers
52 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
68 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 ...
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1answer
49 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 ...
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4answers
156 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 ...
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3answers
77 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 ...
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1answer
73 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 ...
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2answers
81 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 ...
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3answers
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What would happen if someone had a telescope and watched Betelgeuse when it goes supernova?

Would that person go blind? Neutrino detectors and the abundance of Neutrinos would detect the upcoming visible show about 3 hours before any visible signs, so there would be time to point certain ...
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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 ...
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1answer
163 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 ...
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2answers
112 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 ...
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2answers
227 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 ...
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2answers
62 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
94 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 ...
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2answers
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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 ...
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4answers
456 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,...
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2answers
62 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 ...
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132 views

How would astronomical seeing on Mars differ from that on Earth?

Astronomical seeing is the limiting factor for the resolution of all but the smallest Earthbound telescopes. Source Stunning advances in adaptive optics (along with it's predecessor speckle ...
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1answer
143 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.
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1answer
95 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
69 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 ...
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2answers
51 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) ...
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3answers
148 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 ...
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1answer
89 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 ...
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4answers
198 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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2answers
232 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 ...
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1answer
118 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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1answer
154 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.
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1answer
67 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-...
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2answers
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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 ...
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5answers
135 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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1answer
44 views

Celestron Astromaster EQ130

I recently purchased a Celestron Astromaster EQ130 telescope and have absolutely no clue about telescopes but would love to learn. I have set this up but cannot even get a decent view of the moon, any ...