Questions tagged [telescope]

Questions related to the physical instruments for astronomical observations.

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0answers
39 views

Please Help Me With Choosing my 1st Telescope

I'm going to buy my 1st telescope. With the budget, I've shortlisted some. Tried with the YT videos, reviews and guide. Few things still bugging me. Hope somebody can give me any advice on this. There ...
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1answer
78 views

Telescope showing high chromatic aberration

Hi i have made a telescope with 1100 mm focal length objective lense and 21mm plano convex as eyepiece. Both these lenses are not achromatic. But when is looked through it , the images were completely ...
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Can you attach an old Vixen model to a celestron tripod?

I would like to know if I can put an old Vixen VMC model (15 years old) onto a celestron 4se tripod. I am aware that some adaptations must be made, but I want to know if it's even possible or if it ...
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1answer
63 views

Diameter of the moon from the diameter seen in the telescope

I'm reading a chapter on convex lenses and it has this diagram: The chapter explains that triangles ABC and ADE are similar. Thus, ratio of CB to DE is equal to the ratio of BA to AD. Does this mean ...
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1answer
175 views

Why telescope mirror glass shipped as randomly broken chunks of a constant size in cardboard boxes?

The video MIRROR LAB: Preparing for Casting GMT's Mirror 6 shows the unpacking several hundred boxes full of broken glass from OHARA, packed in styrofoam. The glass chunks are a fairly uniform size of ...
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64 views

Tradeoffs "upgrading" from a 60/900 refractor to a 150/1200 Dobsonian?

My current/previous telescope is a Skywatcher 60/900 refractor on an equatorial mount. I am now looking at a SkyWatcher 150/1200 "Classic" Dobsonian reflector. How can I compare the two in ...
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0answers
32 views

Convert Object Intensity to Pixel Intensity

If I have an object of some size and spectral radiance, and it's some distance R from a camera, how would I calculate its digital count value in an image? I'm sure there's an equation out there, but I ...
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51 views

Benefits to adding a 32mm Pössl to my Celestron AstroMaster 130EQ's eyepieces?

I am getting a Celestron AstroMaster 130EQ soon. I have heard that its eyepieces aren't the best, so I am considering a 32mm Pössl. For such a choice, what would be the arguments for and against? How ...
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1answer
61 views

Maritime telescopes: Stabilisation requirements for optical vs. radio telescopes?

SOFIA stands for Stratospheric Observatory for Infrared Astronomy. She says: My telescope stays stable with a spherical bearing, shock absorbers, and gyroscopes. I suppose a similar system would ...
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162 views

Celestron uncommon DC long barrel connector

I have tried to connect a 12v DC adaptor and also a battery pack to my telescope unsuccessfully. Sadly it seems Celestron DC jack needs to be around 2mm longer than common 5525 DC ports. I was ...
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41 views

What are recent discoveries with Earth-based radar telescopes?

The Wikipedia article on radar astronomy lists a few important discoveries using radar technology in general, i.e. also using space-crafts: The following is a list of planetary bodies that have been ...
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1answer
191 views

Can I see Jupiter, Saturn, Mars and Venus with the Spectra Optics Telescope 600x50? [duplicate]

Is it possible to see Jupiter, Saturn, Mars and Venus with the Spectra Optics Telescope 600x50? And even the moon? This is the description of the telescope: User-friendly and easy to install with ...
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2answers
163 views

Can I see Jupiter, Mars and Saturn through the National Geographic 76/350 Dobsonian Telescope?

Is it possible to see Mars, Jupiter and Saturn through the National Geographic 76/350 Dobsonian Telescope? It's the most affordable telescope I can get at the moment. Also, what about the moon? Will ...
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1answer
31 views

Is sky-glow affected by height?

I'm an architecture student and my graduation project will consist of building a research center for outer space, my question is whether or not height would affect sky-glow or not ? Thanks in advance, ...
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1answer
91 views

How to connect my phone to a motorized telescope via a cable?

Some motorized telescopes (e.g. Celestron NexStar Series) have no WiFi by default. Can I connect my phone to them to be used as a hand control via a cable? The telescopes have AUX port and phones USB ...
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4answers
3k views

Why can't we build a huge stationary optical telescope inside a depression similar to the FAST?

So first we'll have to find a natural depression or we should create one. I understand you can only see a single portion of the sky since it can't be moved, so my money is on creating an artificial ...
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55 views

Can the "haze" of a mirror telescope be quantified?

When reading Why was StDr56 discovered only now? and its answers and comments, I realized that refractor telescopes, and in particular the Dragonfly Telephoto Array are a great tool to find nebula and ...
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1answer
75 views

What eyepiece to use for moon?

I'm using a 95mm f/8.4 telescope. What's the best eyepiece that I can buy for a very close look at the moon or even planets? I'm a beginner in this field so please help me. Thank you.
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3answers
565 views

Can we visually perceive exoplanet transits with amateur telescopes?

Is it possible for an amateur astronomer to visually perceive an exoplanet transit by the change of brightness of the star via observations spaced over time, or is the variation of the brightness too ...
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1answer
95 views

Fresnel lenses for a makeshift Galilei telescope?

For a kindergarden (pirate) party, friends of me want to build together with the 4 year old kids a functional pirate's telescope for each of the kids. On the web I found full constuction sets, e.g. ...
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1answer
69 views

How do we differentiate between a star or planet and noise introduced due to equipment?

I understand that differentiating between celestial bodies and noise due to equipment is a fundamental problem in astronomy. I also understand that we solve this problem by looking at something called ...
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2answers
86 views

Using a refractor telescope 5" aperture, 900mm focal length for terrestrial viewing

Can I use a refractor telescope 5" aperture, 900mm focal length on an equatorial mount for terrestrial viewing.
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2answers
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Understanding energy loss in a telescope aperture due to atmospheric dispersion

I'm trying to understand energy losses due to atmospheric dispersion, given the plot below from the Keck telescope. For a typical seeing I'm told that there's 80% encircled energy in 1". The ...
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1answer
64 views

Telescope lens problem when cold

We are having a problem with our scopes on cold nights. (-10F is about average here.) One poorly aimed breath means that the eyepiece lens fogs. We have to remove the lens and keep it under our arms ...
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2answers
416 views

Upgrade tripod on a cheap telescope

I got a cheap refractor as a present - my intro to astronomy. I think it’s not great, but I’m having plenty of fun looking at the moon and planets, and who knows, maybe some other objects soon. The ...
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2answers
127 views

Is it possible to use Photolithography for telescope image sensor?

The current largest digital CCD camera is the Vera C. Rubin Observatory, which has a whopping 3.2 gigapixels with a pixel size of 10 micrometers. In contrast, Agfa 10E56 holographic film has a ...
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1answer
127 views

What is the size of the image sensor in the largest optical telescopes?

What image sensors (imaging electronics) are used in telescopes? Like CCD, is that the best option? What is the typical physical size and resolution of the photo-sensitive surface of the currently ...
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2answers
146 views

How difficult is it for an amateur to discover a new exoplanet or astronomical object?

I recently read about precovery, where plates or images of an object predating its discovery are used to precisely determine its orbit. It occurred to me that it might be possible that some objects ...
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1answer
60 views

Limits of space telescope?

Watching this video describing the "next generation" space telescope, it seems like the biggest mirror will be ~6 meters in diameter. Theoretically, if a telescope was built in space instead ...
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1answer
71 views

Is there a common metric to measure telescope power?

It is rather hard for me to compare telescopes due to the various numbers used. 600mm focal length and a 50mm diameter and eyepiece is a 12mm. VS. Focal length of 500 mm and the objective diameter is ...
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61 views

Question about telescope eyepieces

I have a Celestron 60LCM refractor telescope. It has a 60mm aperture and a 700mm focal length. It came with two eyepieces. One is 25mm and the other is 9mm. They are marked only with their focal ...
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1answer
166 views

How to estimate my eyepiece FOV?

As a follow-on to my question about seeing Jupiter and Saturn at the same time in my scope, I'd like to ask how I might determine the Field of View (FOV) of my eyepieces. More specifically, I'd like ...
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2answers
253 views

Will I be able to see both Jupiter and Saturn at the same time in my Astromaster 114?

I have a Celestron Astromaster 114 Newtonian reflector telescope. The specs: aperture: 114mm focal length: 1000mm focal ratio: f/8.77 I also have a t-ring so I can connect a Nikon camera to it. Will ...
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5answers
3k views

Is it possible to do planet observation during the day?

Keep in mind I'm just a newbie. So.... I have a new Newtonian telescope. It has 150mm opening and 1400mm Focal Distance on top of an equatorial mount. I have 25 and 10 mm eyepieces... and a 2x Barlow. ...
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0answers
47 views

Sky-Watcher Dobsonian 16 Inch Synscan Go-To [closed]

What is the best way to buy Dobsonian telescope 16‘? Where can I buy it new or used? What I will need to have in advance? Which negative sides it has? Please, share any information you have about this ...
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3answers
101 views

Why are telescope mirrors nearly flat?

My understanding of telescope mirrors is that they are (generally speaking) a slice out of an imaginary sphere. The center of this sphere is the focal point of the telescope, where the detector is ...
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1answer
93 views

Difficulty in using the telescope as a projector

I have been trying, but completely failing, to copy the arrangement for viewing the sun mentioned on this website: https://astronomyconnect.com/forums/articles/2-three-ways-to-safely-observe-the-sun....
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1answer
166 views

Can equatorial mounts be used at lower latitudes?

I wanted to order a Celestron 127EQ and I was going through the manual online and just noticed that the manual says that latitude is adjustable in about a 20-60° range. The PowerSeeker equatorial ...
2
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1answer
336 views

Eyepiece recommendation for Orion XT8

I am looking for some eyepiece recommendations for my Orion XT8. There are so many kinds out there, and I am not quite sure what to get as recommendations vary wildly. Here are some Q&As that ...
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4answers
3k views

What will succeed the Arecibo Observatory?

Just a few minutes ago, I got a notification from Space.com stating that the Arecibo Observatory will be, sadly, decommissioned due to extensive damage to its structure. So, with the loss of one of ...
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0answers
90 views

How long would it take to first detect a new object in the night sky given its apparent magnitude?

If an object as bright as the star Polaris (Apparent Magnitude +1.8) showed up in the night sky, it would be detected almost instantly by stargazers. If an object as bright as Pluto (Apparent ...
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3answers
128 views

What's the farthest point humans have explored?

By using powerful telescopes on land and space, what's the farthest point humans have explored or viewed?
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1answer
236 views

Eyepieces and accessories recommendations for a Starblast 4.5-inch scope in a city as well as darker suburbs, and kid friendly?

For the Starblast 4.5 Telescope I currently have an Orion 7-21mm Zoom eyepiece attached on top of a 2x Barlow lens. I like them because of the magnification they give stacked together and the zoom ...
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2answers
4k views

Please check my Mars photo

Hi built my own newtonian telescope for the first time. Up until that point I had never used a telescope. Can you please look at the photos attached and tell me if this is what Mars should look like ...
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2answers
294 views

How to use an app to help find deep sky objects in general, either attached to a telescope as a finder scope or held on hand?

A friend with a young child asked me for a beginner scope recommendation of less than $300 to see the planets as well as some brighter deep sky objects in a relatively dark suburban location. My first ...
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1answer
51 views

What is an Ideal apparent field of view for viewing planets through a zoom eyepiece?

I was reading the specs of a few zoom eyepieces, and in every eyepiece, there is a term called 'apparent field of view'. I looked up and searched about it and figured out that if you divide this by ...
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4answers
7k views

Shouldn't this cause a fire?

This website shows a telescope projecting the sun onto a blackboard: https://astronomyconnect.com/forums/articles/2-three-ways-to-safely-observe-the-sun.21/ Why isn't the board catching fire? You ...
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1answer
247 views

Mars is dark, surrounding is bright, what am I doing wrong? [duplicate]

I just got a Celestron 8 and I'm a complete rookie: set up scope early so it would acclimate to the temperature. No difficulty locating Mars, but I see a dark planet with its circumference slightly ...
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2answers
236 views

Would alcohol wiping damage multi-coated eyepiece coating? How else can I take COVID precautions on the eyepiece?

My small group of friends will be wearing masks. But could COVID-19 be spread by eyes/eyelashes touching the eyepiece? If so, what precautions should I take? I have a small Starblast scope with an ...
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1answer
142 views

How to make a 65 cm lens with a 20 cm hole in it for a Hamiltonian telescope?

This answer to What (the heck) is a Hamiltonian telescope? Is this one? confirms that the telescope in the question linked there is indeed as described and that the first lens is a full 65 cm aperture ...

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