Questions tagged [telescope]

Questions related to the physical instruments for astronomical observations.

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1answer
47 views

Advice for next steps with astrophotography

Over the last year, I have started to take up the hobby of astrophotography. At the moment I have been focused on planetary astrophotography. Up until now I have been using a Celestron 5SE telescope (...
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2answers
112 views

How come I can point to two places with telescope and have the same coordinates?

Absolute beginner here. I read through the telescope manual, watched many videos, and got a pretty decent understanding of DEC and R.A. However, I don't understand one thing (where theory doesn't ...
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1answer
87 views

If Proxima Centauri was replace with a quasi-star, would our telescopes be able to see it in fine detail?

Quasi-stars, if they ever existed, were stupid big and stupid bright; many times bigger, brighter, and more massive than any star supported by fusion can be. There's no question that it could be seen ...
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3answers
5k views

Can large scientific telescopes observe the Moon without being damaged?

When I look at the full Moon through my 10cm telescope, it is so bright that it hurts. Can large scientific telescopes observe the moon at all? Does that require special protection equipment? Or ...
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1answer
76 views

Tracking deep sky objects

I have a Celestron Astromaster 130Eq. I saw all the planets in our solar system and quite satisfied. Now I am in the hunt for DSOs, but living in a city is a disaster for tracking some good-for-...
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1answer
44 views

Schmidt corrector plate on a Newtonian = Schmidt Cassegrain?

Went on with a wide range of telescopes and its mechanics. To my understanding, the only change in the optical function in Schmidt Cassegrain telescope is a Schmidt's corrector plate in front of an ...
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1answer
142 views

Not getting quality images in telescope

New to astronomy, I have a Newtonian telescope (Celestron 130 eq) with 5.2 inch (~132 mm) aperture with 650 mm focal length, Spherical mirror. And having 4mm, 10mm, 12.5mm, 20mm,20mm (erecting ...
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0answers
35 views

What is the difference between a Cassegrain telescope and a Gregorian one? Which one is better?

Of the three giant (or 'Extremely Large') new telescopes being built, the Thirty-Meter (TMT), the the Giant Magellan (GMT) and the Extremely Large Telescope (ELT), only the Magellan, from what I ...
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1answer
54 views

How to determine the color term for a filter with a systematically bluer offset than the standard

This is a hypothetical scenario in an attempt to test my understanding of the color term when performing photometric calibrations: Imagine we are observing stars through a B filter with an offset ...
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Would Atlas Pro's prediction about the color of plant in Kepler-186F work as a biosignature to search for life?

The Atlas Pro video that prompted this question is this. Tl;dr: it is argued that due to the different spectrum of radiation emitted by Kepler-186 and what is known about the evolution of ...
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Can you advise on the construction of a large segmented primary mirror (hobbiest)?

I am interested in experimenting with the building of a large parabolic primary mirror constructed from 4" hexagon mirrors mounted on a "rough" parabolic surface with either 3 screw ...
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Database capable of determining or predicting tumble of space debris

The tumble of space debris will need to be understood before large scale, active debris removal missions can be carried out. Tumble is really hard to precisely determine because most debris has lost ...
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A new (radio) neutrino telescope in Greenland?

I just stumbled upon ScienceMag news from July 14th, 2021 which says: By placing hundreds of radio antennas on the ice surface and dozens of meters below it, they hope to trap elusive particles known ...
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3answers
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Do telescope measurements (in meters, usually) measure in a straight line, from edge to edge, or follow the curve of the mirror?

Somehow, no site or book or magazine has clarified this question for me.... Perhaps I am an idiot, but, Is the parabolic primary mirror on the new James Webb Space Telescope (JWST) 6.5 meters from ...
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1answer
67 views

If the visibility function is the Fourier transform of the sky brightness distribution, why do you need the dirty beam and dirty image to find it?

In radio astronomy, the dirty image is equal to the inverse Fourier transform of the uv-plane coverage times the sampled visibilities. The dirty image is also equal to the convolution of the "...
4
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1answer
81 views

Is there a complete guide on how to use telescopes?

tl;dr As said by @uhoh in the comments, is there A Big Book of Telescopes? i.e: Is there some kind of media that gives a complete treatment to telescopes? I am relatively new to Astronomy.SE. I wanted ...
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2answers
748 views

What can I see with different apertures?

I'm looking to buy a telescope, and every mainstream website says that aperture is the most important factor, and buy the largest telescope your budget can afford. However, a website I found offering ...
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1answer
68 views

How common are telescopes with the finder scope on the right side?

Are there telescopes where the finder scope is mounted on the (upper) right of the body? Are they common? If not, are there any ways around this (e.g. can I mount a lightweight telescope "...
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3answers
112 views

Can a hydrogen bomb explosion be seen from every distance?

When we use the strongest optic telescope available, how far from Earth can a hydrogen bomb explode in space and be visible for this telescope? Is there a fundamental limit to this distance? Even for ...
2
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1answer
47 views

2001 VB - when will it be reacquired?

2001 VB's orbit is poorly known but has a two-in-a-billion risk of a collision with the earth in 2023. Assuming that it were on a collision course, when would it be likely to be reacquired? Which ...
5
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2answers
102 views

Can the transit of satellite in front of Sun be visible in 10-inch telescope?

I have 10 inch Sky-Watcher telescope and I would like to know if a satellite passing in front of Sun can be visible. Suppose that satellite's angular diameter is 1˝. Yes, I know the formula $\theta=\...
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62 views

Would a possible accretion disk around a primordial black hole 500 au from the Sun be visible in present telescopes?

If the hypothetical two-inch black hole 500 au from the Sun had an accretion disk, might current telescopes detect it already or do we have to wait till the Vera Rubin Observatory starts work?
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1answer
44 views

Why did the famous Multiple Mirror Telescope (MMT) get rid of them and become the Massive Monolithic Telescope?

Popular Science's 2016 article The silliest names scientists have given very serious telescopes... Ranked! says: Arizona’s MMT Observatory used to house the Multiple Mirror Telescope. In 1998, ...
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1answer
86 views

How much of M87 can i see with an amateur telescope?

I was reading about M87 and how it is possible to see it's relativistic jet with an amateur telescope. About a year ago i impulse-bought a telescope (model: Celestron CE21049 powerseeker 127EQ). I'm ...
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1answer
92 views

Can we get a picture of Oumuamua with Hubble Space Telescope?

Can we get a picture of Oumuamua with Hubble Space Telescope? If not, what are the reasons? Answers why other telescopes might fail to get a picture of Oumuamua are welcomed as well.
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56 views

Safety while using a telescope to view a total solar eclipse

I have an 8-inch reflector telescope and a solar filter that goes on the front aperture to view the Sun (most recently to view the transit of Mercury). If I were to use this telescope during a total ...
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1answer
67 views

Do telescopes exist that reflect the incoming light more than three times along their length?

Refractors only use the length of the telescope once, reflectors twice, catadioptric telescopes like those of the Schmidt-Cassegrain design three times. Have telescopes been built that reflect the ...
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1answer
72 views

Do triple or more times reflecting telescopes exist?

Refractors only use the length of the telescope once, reflectors twice, catadioptric telescopes like those of the Schmidt-Cassegrain design three times. Have telescopes been built that reflect the ...
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1answer
112 views

How do I design a good telescope to observe nebulae and other deep sky objects [closed]

How can I make a good telescope that is powerful enough show nebulae and other deep sky objects ? (consider low budget build)
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1answer
34 views

Given telescope diameter and focal length only, how can I find the size of a produced image?

I'm new to astronomy and I'm struggling to understand this concept. For example, A 20-cm diameter telescope with a focal length f = 2 meters produces an image of the moon 1.7 cm in diameter. How large ...
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3answers
2k views

Telescope on drones to escape light pollution?

Would it be possible to mount a telescope on a high quality drone and fly above the light pollution to get better star shots (if the wind allows it of course)?
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6answers
6k views

Why do small mirror imperfections matter with modern computers

Modern telescopes go to great lengths to have perfectly shaped parabolic mirrors. My question is, why go to the trouble of having a perfect mirror? Why not take a mirror roughly the right shape, and ...
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1answer
59 views

How to reduce magnification and increase FOV of a camera attached to a telescope?

I am a beginner in astronomy. I have a Maksutov telescope (90mm/1250mm). Generally I do observation with a 25mm wide angle eyepiece, but sometimes due to light pollution I can't see many stars. So I ...
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1answer
118 views

Where can I find Arecibo's data archive?

Does anyone know where I can find Arecibo's historical data? After much searching, I can find neither hide nor hair of it. It doesn't help that the search results are completely dominated by the news ...
9
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1answer
622 views

Is it possible to observe strong gravitational lensing with amateur telescopes?

Strong gravitational lens systems like the Cosmic Horseshoe have been imaged by scientific space telescopes, but have any amateur astronomers accomplished this? Or are amateur/small ground based ...
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2answers
84 views

How are non-visible electromagnetic waves detected that originate from space?

How are non-visible electromagnetic waves from space detected and interpreted by the receiver? Is it in the same manner, as say radio waves produced on Earth, where the EM wave interacts with the ...
5
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1answer
106 views

Is Cosmic Ray Astronomy a thing?

Historically astronomy has been the regime of visible light, looking at distant objects in the visible spectrum and later taking photographs in the visible spectrum. In the past century radio ...
22
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4answers
8k views

Why is Starlink polluting the night sky a big concern if we have space telescopes?

There's a lot of concern in the Astronomy community over the deployment of Starlink satellites. For a good discussion, see the related question How will Starlink affect observational astronomy? But ...
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1answer
72 views

Hypothetically, could a civilization in a solar system near a supermassive blackhole use the blackhole as a huge gravity lens telescope?

I have heard of various proposals that use the massive gravity of stars to sort of focus light at and observe with a suitable telescope placed at such a distance, and I am assuming here that bigger ...
3
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2answers
58 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 ...
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0answers
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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 ...
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59 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 ...
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1answer
102 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 ...
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1answer
69 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 ...
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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 ...
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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 ...
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1answer
46 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 ...
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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 ...
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2answers
235 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?
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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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