Questions related to the physical instruments for astronomical observations.

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3
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1answer
67 views

Focusing light through plastic cable to extend telescope viewer

This question will seem out of place here, my explanation is that I want to build a system to view my telescope without being uncomfortable, as of now I have to stand up and bend over to view the eye ...
5
votes
1answer
35 views

How much competition there is for jobs in astronomy compared to other fields of science?

I will soon finish a master's degree in computer science. I have been interested in astronomy for some time, which has included playing around with a Newtonian reflector telescope and reading about ...
3
votes
1answer
59 views

Moving from computerised to normal amateur telescope?

A few years ago I purchased a Celestron Nexstar 130 SLT computerised telescope thinking that it would be a perfect to get me into astronomy. The issue is the computer doesn't work at all and manually ...
0
votes
2answers
31 views

Tunnel vision while viewing through a reflector

I have a Celestron astromaster130 eq. While viewing through its eyepiece, or using a smartphone camera for photography purpose there is always a definitive no light region( it is circular in ...
2
votes
0answers
17 views

Telescope optical tolerance from central axis

I sometimes encounter telescopes/binoculars with a decent objective diameter but are very difficult to use because they only work when the eye is looking down the central axis (i.e. in the centre of ...
0
votes
1answer
64 views

Jupiter appearing odd through a 6" reflector

Recently I have been trying to get a good look at Jupiter through my 6" Orion reflector, but the image seems to always come out as an oblong white streak. I've tried changing the lenses I'm using, but ...
0
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1answer
33 views

How do I see DSO's in my telescope? [duplicate]

I just bought a new telescope. I tried it out, and I even woke up at 3am when the moon set so there was light pollution. I have an 8 inch dobsonian telescope with a focal length of 1200 mm. For some ...
0
votes
1answer
80 views

How do I see more than just points in the sky?

I just bought a new telescope with these specifications: Aperture: 203 mm Focal Length: 1200 mm F/ratio: f/5.9 I usually use a 28 mm eyepiece, giving me about 42.5x magnification, but I also have ...
0
votes
1answer
36 views

Radio telescope targeting

How do you target a radio telescope on the precise object you wish to observe? You can point it in the general direction but how do you get the information from the exact point in the sky that you are ...
0
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1answer
100 views

Why would astronomers want to eclipse the Sun?

I've heard that some astronomers are building an artifical solar-eclipse ship, that should help us to dim the diffraction of the Sun. Why don't we just wait till night? What is the function of the ...
2
votes
1answer
65 views

Given a collection of pixels, how to deduce the flux from them?

I've obtained the coordinates of brightest pixels from different images (.fits files) using Python. I want to get the flux of each pixel. How do I go about finding out the flux?
1
vote
2answers
32 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 ...
1
vote
1answer
67 views

Telescope choice

Which one is better? Features: 1)Magnification: 18x - 90x Eyepiece Diameter: 5mm (18x), 10mm (60x) Objective Diameter: 50mm Focal Length: 36cm Tripod Height: 38cm Main tube Color: Silver Net ...
5
votes
3answers
106 views

Could mirrors be replaced with CCDs?

Why do telescopes use mirrors that simply reflect photons, when they instead could be covered with large sensors to register them? Reflection is all good and well, all thanks to silver and beryllium ...
6
votes
0answers
122 views

Method to determine the amount of reflected starlight necessary for an exoplanet to be visible from a given distance/angle?

What is the method to determine the amount of reflected starlight necessary for an exoplanet to be visible from a given distance/angle? (Not from occlusion but actually visible on its own.) Further, ...
1
vote
1answer
38 views

The moon: how to determine its size, speed and distance from earth using a simple telescope?

Assuming I only have a simple telescope, how can I determine the size of the moon, its angular velocity and distance from earth?
0
votes
0answers
79 views

Buying telescope online [duplicate]

I'm trying to buy a telescope online but I'm afraid of scams. What is the minimum magnification required to view celestial objects like the rings of Saturn or the asteroid belt? Here are the details ...
6
votes
1answer
40 views

Infrared Region Telescopes

Why do we need to build telescopes that can view in the infrared? What exactly do we need to see in the infrared region? I know this seems like a really broad question but I'm just curious about it.
2
votes
1answer
142 views

Power of the James Webb Space Telescope [duplicate]

I have heard that the JWST will be capable of looking at the early stages of the universe. However I have also heard that it won't be capable of detecting the Oort Cloud that supposedly provides ...
4
votes
1answer
44 views

Has THC been detected in space?

I was wondering if and how astronomers have/had detected the molecule Tetrahydrocannabinol (THC), commonly known for it's effects in marijuana, in space. I had previously seen a hoax regarding the ...
4
votes
0answers
52 views

3000th Question: What does the future of astronomy look like with the next generation of telescopes? [closed]

What will the benefits and advantages be of the upcoming generation of telescopes such as LSST, E-ELT and JWST? And more broadly where will this leave astronomy in 10-20 years time? This isn't a ...
1
vote
2answers
50 views

What is the longest observable wavelength of light using an optical telescope?

How far outside the visible spectrum could an optical telescope feasibly operate?
1
vote
2answers
89 views

Dish antenna as parabolic mirror for OPTICAL telescope?

Can i use a chrome painted dish tv antenna as a parabolic reflector for my Optical telescope ? Given that glass mirrors are quite expensive, i am thinking of using a Dish TV antenna and coating its ...
0
votes
0answers
16 views

How useful are filters for spotting nebulae?

Recently I've been trying to spot a couple of nebulae, IC59 and IC1318. The skies at the site are modestly dark (4.5 on the Bortle scale), I'm using an 8" scope, and I've slowly scanned around the ...
3
votes
2answers
105 views

What are the advantages and disadvantages of a 2-inch eyepiece versus a 1.25-inch eyepiece?

I'm considering picking up some new eyepieces for my telescope and am interested in comparing 2-inch and 1.25-inch eyepieces. Are there any disadvantages to 2-inch eyepieces? Are 2-inch eyepieces only ...
2
votes
1answer
35 views

Can angular information be known more precisely than the diffraction limit?

The diffraction limit deals with the ability to determine if two things are separate. I am interested in the ability to find the the centroid of a single object. Imagine a star with no near ...
5
votes
1answer
55 views

What visual artifacts are expected from the JWST?

What visual artifacts should we expect from the images that will be released from the James Webb Space Telescope? Specifically, do we expect 3-pronged diffraction spikes (any preview how they would ...
3
votes
1answer
26 views

What is the formulat to compute King tracking rate for a given set of topocentric coordinates?

Canbury Tech has a good background on King tracking rate, which approximates the average sidereal motion of a refracted star across the sky. Most amateur telescope mounts have some sort of notion of ...
5
votes
2answers
146 views

Why when we look through a telescope in space, do the billions of stars not block our view from seeing further?

I know that we are able to "see back into time" by looking very far away through telescopes such as the Hubble telescope, but my question is, wouldn't you run into at least a couple of stars that were ...
9
votes
1answer
201 views

What is the bluest narrow band filter mounted on ground based telescopes?

If we want to check a QSO's lyman alpha narrow band image, could a ground based telescope do that? I mean under the circumstance that its lyman alpha shifts to 3300A.
10
votes
4answers
343 views

Using the Sun as a Gravitational Lens

Can the Sun be used as a gravitational lens to achieve better telescopic viewing? Can this effect be practically used to view celestial objects?
0
votes
1answer
58 views

Identify this 2 axis motorized tripod

I am NOT an astronomy person, so this may be a dumb question, however I have recently found a tripod that appears to be for star tracking as far as I can guess. I would like to know the type of tripod ...
6
votes
2answers
152 views

Ninth planet - what else could it be?

So recently it was announced that there might be a ninth planet out there. Some people (from NASA) say the odds are 50% that it is a real planet, since it hasn't been discovered by telescopes yet. ...
2
votes
2answers
10k views

How much magnification is needed to see planets of solar system?

I have a 3inch Newtonian reflector telescope with 300 mm focal length. I can use highest magnification of 75x using a 4mm eyepiece. But in 75x I can't see details of Jupiter what was expected. Instead ...
4
votes
3answers
674 views

Telescope buying guide for a beginner in India

I am located in the southern part of India and am looking forward to buy a telescope to gaze up to look ay farther planets, moons in our solar system and take pictures. How should I go about getting a ...
1
vote
1answer
78 views

Beginner telescope for my daughter [closed]

My husband and I are trying to figure out what type of telescope to get our young daughter. We would like to be able to see planets but nothing too extreme. Just something to get her started. She has ...
2
votes
2answers
57 views

What was the largest telescope ever fitted with an eyepiece

Serious modern telescopes use CCDs to capture the results. This makes it convenient to process or display the results halfway around the world. However, there is something visceral about looking ...
17
votes
7answers
3k views

How can we focus radio telescopes on a star when the earth is spinning?

Reading about the Star KIC 8462852, it has been said that the SETI project turned its radio telescopes towards the star to search for extra terrestrial radio signals as the star had strange ...
1
vote
1answer
37 views

How are the gaps filled in images captured by CCD arrays?

Large telescopes don't use a single CCD; they use arrays of them. Since CCDs can't be seamlessly joined, this means that every captured image must have gaps. But, the resulting images almost never ...
5
votes
1answer
50 views

Diameter of Astronomical Object Using Magnification

I took a picture of Jupiter through my telescope, using an iPhone. I know the magnification of the telescope lens I used, and can Google to get the magnification of the iPhone lens (the magnification ...
2
votes
2answers
76 views

When is Gamma Draconis closest to the zenith in London on April 4th

I am reading Roobert Hooke's paper An attempt to prove the motion of the earth from observations (1674, faksimile). Hooke writes The principal dayes of doing which will be about the 4 of April, ...
3
votes
2answers
301 views

Equation to find distance between objective and eyepiece

I have a home made astronomical telescope with 100 cm objective lens and 5 cm eyepiece.when viewing an object in infinity the distance between eyepiece and objective is 105 cm. So how could I ...
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vote
0answers
48 views

What would be the maximum theoretically possible angular resolution?

I have studied some basic astronomy, but I have difficulty conceptualizing the physics of luminosity and optics. We use electromagnetic spectra to detect existence and properties of distant planets, ...
4
votes
1answer
420 views

How many bodies can I see with a 90x telescope?

I am a 9th class student so I'm a beginner at using a telescope, hence please help me. How many bodies can I see using a 90x telescope? How will I know when and where I should point a telescope to ...
2
votes
2answers
53 views

Astronomical telescope making

I am thinking about making a telescope. I have a 100cm focal length lens which I can use as objective lens in my telescope. So which is the best focal length I can use as eyepiece in my astronomical ...
1
vote
0answers
9 views

What makes small interferometers useful? Like NIRISS on JWST

NIRISS is an instrument on the James Webb Space Telescope. It has a "non-redundant aperture mask" which obviously covers most of the area of the sensor. It seems to be advantageous for high contrast ...
7
votes
1answer
185 views

Theoretically, what is the biggest optical telescope that may exist?

Recently, I read yet another news about E-ELT. It will have 39.3-metre-diameter segmented primary mirror. And I was interested in the next question: Theoretically, what size of the primary mirror ...
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vote
0answers
25 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 ...
4
votes
1answer
103 views

Telescope collimation issue

Recently I purchase Chinese 8 inch reflector telescope from local store. When I observing starts and planets I've been having trouble getting really sharp image from this telescope. I observe Venus ...
1
vote
1answer
153 views

Calculate Dec and RA of a star from Euler angles and GPS data

I have 9DOF sensor (accelerometer, gyroscope, and magnetometer) that gives orientation via Euler angles (yaw, pitch, roll). Along with GPS data (latitude, longitude, elevation, time) this is passed to ...