Questions tagged [telescope]

Questions related to the physical instruments for astronomical observations.

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3
votes
1answer
28 views

Plotting Equatorial coordinates to X,Y plane (simulating telescope/camera view)

I would like to simulate a telescope camera view, projecting (RA, Dec) coordinate sets to a 2D plane. So effectively the need is to convert Equatorial coordinates to (x, y) coordinates, when we can ...
1
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0answers
11 views

Convert apparent magnitude in a filter to a luminosity

I have data in Johnson B & V filters and I would like to convert the observed magnitudes, m$_x$, into luminosities, L$_x$, over a passband where I already know the distance, d, to the object. x is ...
4
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0answers
53 views

What to do in case of concentric circles that are not aligned with the cross after collimation (Picture inside)?

I have been collimating my newly bought first Newtonian telescope for a few days now, but I can't get the center of the circles to align with the intersection point of the spider's reflection. I have ...
1
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1answer
46 views

How did I flip some mirrors around in the dark at 3 AM and change the focal length of a 24 inch Boller and Chivens?

Current answer(s) to How do telescopes "zoom" and change angle of view? are "they don't", but traditional large genera-purpose observatory telescopes do sometimes (often?) have ...
2
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1answer
43 views

Are X-ray telescopes with glancing angle surfaces basically “funny-looking” Cassegrain telescopes mathematically?

In this answer I included the image below of a reflective X-ray telescope. It is made from two elements; the first is concentric shells of glancing (high incidence) angle paraboloidal surfaces, and ...
2
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0answers
40 views

Size of crosshair

TL;DR: Does anybody know the width of a single crosshair as a fraction of the full field of view on a Skywatcher 1.25 inch 12.5mm illuminated reticle? Explanation (in case there's a different question ...
1
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0answers
31 views

What happens to the Fourier Transform of the Measured Spectrum?

What happens when you double the width of the entrance slit of a spectrograph, in turn letting in twice as much light, would there be an improvement in the Fourier transform of the measured spectral ...
2
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0answers
15 views

Custom INDI client & Telescope control

I have started building my own INDI client library in dotnet standard C# to remotely control my Celestron NexStar 5SE telescope. If you want to see my client code it can be found here on github. My ...
2
votes
1answer
36 views

Limiting magnitudes for different telescopes

I live in an extremely light polluted place. On a new moon night, magnitude 3.5 stars are at the limit of naked eye visiblity on clear nights, and the Orion nebula is visible as a smudge through my ...
1
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0answers
16 views

Spectrograph Arrangement, Noise, and Fourier Domain [closed]

If the transform of a line profile extends out to the Nyquist frequency such that we cannot see the noise level, what could we change in our spectrograph arrangement that would allow us to see the ...
5
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2answers
123 views

What is the gain of a telescope?

What is the gain of a telescope? How would I go about calculating the gain from a flatfield image?
0
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0answers
37 views

Celestron Inspire 80az

I am new to stargazing, so I am unsure of what I am doing. I have an Inspire 80az telescope and 20mm and 10mm lens. I can view the moon really well but would like to view more planets, so I want to ...
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0answers
38 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 ...
2
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1answer
68 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 ...
1
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0answers
35 views

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 ...
3
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1answer
60 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 ...
8
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1answer
164 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 ...
2
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0answers
63 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 ...
2
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0answers
28 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 ...
2
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0answers
43 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 ...
3
votes
1answer
59 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 ...
2
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0answers
160 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 ...
2
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0answers
36 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 ...
2
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1answer
143 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 ...
1
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2answers
101 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 ...
3
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1answer
29 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, ...
4
votes
1answer
52 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 ...
10
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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 ...
3
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0answers
54 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 ...
0
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1answer
48 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.
7
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3answers
557 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 ...
2
votes
1answer
61 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. ...
3
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1answer
64 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 ...
2
votes
2answers
64 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.
3
votes
2answers
55 views

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 ...
2
votes
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 ...
5
votes
2answers
376 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 ...
7
votes
2answers
126 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 ...
7
votes
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 ...
3
votes
2answers
139 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 ...
2
votes
1answer
58 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 ...
3
votes
1answer
70 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 ...
1
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0answers
56 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 ...
1
vote
1answer
90 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 ...
4
votes
2answers
234 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 ...
25
votes
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. ...
1
vote
0answers
44 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 ...
4
votes
3answers
95 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 ...
2
votes
1answer
34 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....
2
votes
1answer
115 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 ...

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