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Questions tagged [amateur-observing]

Questions about the observation of celestial objects by non-professional astronomers.

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4answers
1k views

Can satellites travel in clusters?

Last night we saw a large cluster of what looked like exceptionally bright stars that moved, as a group, across the night sky in Lancaster, PA. It was about 9:15 pm, and they moved roughly from SW to ...
6
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1answer
310 views

Watching the Mercury transit with improvised devices

I have learned that it is not possible to watch the upcoming Mercury transit with the plain eye (using special filter glasses). Is it possible to watch the transit with improvised devices (like a ...
2
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1answer
64 views

What are criteria to compare and evaluate different 12 inch truss Dobsonian telescopes?

What are criteria to compare and evaluate different 12 inch truss Dobsonian telescopes? I'm primarily interested in comparing mirror quality and weight (price I can do myself of course). Two examples ...
3
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3answers
1k 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 ...
2
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1answer
66 views

Seeing a star near zenith around sunset

I'm recalling while taking a university astronomy class the professor brought a few of us up to the observatory, around sunset. He showed us a star near zenith with the telescope. After we left the ...
3
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0answers
60 views

Does it make more sense to upgrade our existing telescope or to buy a new one?

We're at a bit of a crossroads here, since we're faced with what appears to be a tough choice. We've got a Celestron 11" SCT tube with a Losmandy G11 equatorial mount, all bought in 1996. The mount ...
4
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1answer
265 views

Split telescope into two eyes

I am looking for an appendage to attach to the end of a telescope which splits the image into two eyes instead of one. Does such an appendage exist?
7
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3answers
870 views

Calculate the shadow on earth of a large orbital disk

How to calculate the shadow on earth of a large orbital disk (low orbit)?
0
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1answer
73 views

Questions about amateur astrophotographer Nik Szymanek's telescope

The 2011 Sixty Symbols video Spy Satellites (from Deep Sky Videos) shows amateur astrophotographer Nik Szymanek and his telescope. Question: Can someone identify the model and design of this ...
2
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1answer
161 views

Why is this telescope so short? How hard is it to make such a fast primary?

The recently discovered object C/2019 Q4 (Borisov) is in the news because it might have an eccentricity greater than one, which means it might be from outside the solar system, though not necessarily. ...
3
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1answer
105 views

Any simple experiment with an H-alpha telescope?

Is there any simple experiment that can be done with an H-alpha telescope, for example to estimate the Sun's mass, size, distance, temperature or intensity? I give lessons about renewable energy and ...
6
votes
1answer
379 views

How is it ensured that a parabolic shape forms while polishing a telescope mirror?

I understand polishing the mirror with a successively finer abrasive can create a curvature, but how is it possible to obtain a uniform curve that forms a parabola while polishing by hand?
3
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1answer
136 views

Did NASA/JPL get “waning” and “waxing” backwards in this video?

The NASA JPL video What's Up: September 2019 Skywatching Tips from NASA says (per both the closed captions and audio): We’re in a several-month period right now when the new Moon falls right around ...
1
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1answer
84 views

Brightest most colorful star in eastern morning sky not near any constellations; rises about 4 or 5 am?

I have been believing this is Saturn, but perhaps Antares instead? It is so colorful it shines blue, red, green and white. It is largest in sky in the East before dawn rises about 4 or 5 AM, seen ...
3
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0answers
38 views

Textbook advice [closed]

I'm looking for resources/texts to learn more about stars and things. I stopped studying physics when I was 15, so I'm pretty uninformed. However, I do have a pretty good maths background (UG courses ...
2
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1answer
65 views

What's the origin of Clyde Tombaugh's 9-inch Newtonian telescope?

Astronomer Clyde Tombaugh is shown in a now-famous photograph at the age of 24 with his "homemade" 9-inch Newtonian telescope in this image also shown in Elva R. O'Hara's Clyde W. Tombaugh: Farm Boy ...
2
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0answers
32 views

In which countries are there organised Messier Marathons?

Just out of curiosity... In which countries have there been or are current, organised Messier Marathons? Thank you for all answers and effort for this!
0
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1answer
71 views

Does anybody recognize this kind of prism?

Supplemental to this answer to Did Edmund Scientific 4¼ inch Newtonians have 90° prisms as secondary mirrors in the 1970's? I was poking around a bit further and ran across this "1960's Edmund ...
0
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3answers
2k views

What is the first recorded reference to the Moon being a satellite of the Earth?

I saw a list recently of the moons of the various planets and the discoverer(s) and date of discovery. Earth's Moon was listed as Unknown. I know you don't 'discover' a huge disc in the sky. But ...
2
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2answers
111 views

When would we detect a tiny meter size natural satellit in a geostationary orbits?

A natural, tiny (meters-size, maybe 10.000kg mass) natural satellite could be trapped in a geostationary orbit. I wondered for quite some time: When and how are we able to detect these satellites? ...
1
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2answers
53 views

Did Edmund Scientific 4¼ inch Newtonians have 90° prisms as secondary mirrors in the 1970's?

I mentioned my old telescope's secondary mirror in this answer (stiffness) but I'm not certain I am remembering correctly. My first telescope was a Edmund Scientific 4¼ inch Newtonian reflector. This ...
1
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1answer
61 views

How can we estimate if a certain astronomical object will be visible from a place on earth?

If we have the RA/DEC of an object that we want to observe, how can we tell if that object is visible from our place on earth (at a particular time of the year)? Given that the part of the sky we are ...
0
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2answers
107 views

Knowing the RA/DEC of a star how do I locate a star from ground?

Standing in Melbourne at 4 am in the morning on 14th April 2019, Sirus RA = 06h 45m 08.9s, Dec = -16° 42' 58"..How do I Locate this. Standing facing east I turn myself towards south approx 90 Deg and ...
24
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4answers
3k views

Are there any double stars that I can actually see orbit each other?

If I had a nice amateur telescope†, are there any multiple star systems that I could observe over a few years or a few decades and actually see the movement of one or both of them over time? My short ...
2
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0answers
34 views

Requirements for an amplifier and filter for a horn antenna-based 21 cm radio telescope?

We are looking into the possibility of building a low budget horn antenna for detecting 21 cm hydrogen line radiation (~1420 MHz) and and possibly measuring its spectrum. What are the types of ...
5
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1answer
215 views

How big will Apophis appear?

How big will Apophis appear in the sky at its closest point of approach in 2029? Will it compare to the moon? How long will it linger as it passes?
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0answers
72 views

Telescope was working and now it's not

We have a Celestron 70AZ 70mm f/10 refractor that has been working perfectly. Our children knocked it over the other day, and now when we try to view the moon, it ...
2
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1answer
84 views

Custom telescope

I am currently trying to make a Keplerian telescope from "scratch" with plano-convex lenses bought online. I have found my objective and eyepiece lenses. I'm just not sure if they will suffice to ...
0
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1answer
37 views

Plot SuperWasp Lightcurves

I am trying to plot superwasp lightcurves in python from the fits files, using TMID and FLUX2, getting this: There is a way to transform the information so I can plot the lightcurves with the kepler ...
3
votes
2answers
133 views

How to locate nebulas visible through AstroMaster 114 telescope without device assistance?

I will be going to the desert this month and it's my understanding that the night sky will be very dark there. I've got some practice locating the planets but I'd really like to get a look at a nebula ...
3
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0answers
67 views

How to calculate planetary positions hundreds or thousands of years ago

Wondering how to calculate the following in a general way: Sunrise/sunset Equinoxes/solstices Moon phases Planetary positions For hundreds to thousands of years ago. Wondering what the calculation ...
2
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1answer
102 views

Second Telescope: Maksutov Cassegrain vs Refractor

I bought my first telescope, a 3inch refractor a few weeks ago. It has been a wonderful experience seeing the Moon , Jupiter, Satrun magnified and Andromeda, M33, M81 and much more for the first time. ...
13
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2answers
2k views

Is it possible to do moon sighting in advance for 5 years with 100% accuracy? [duplicate]

It is Ramzan and the usual heated disagreements between clerics here in Pakistan as to the sighting of the crescent. This time the minister of Science and Technology (who is not a scientist himself ...
46
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3answers
10k views

If Earth is tilted, why is Polaris always above the same spot?

Why is Polaris, the North Star, always above (or near) the North Pole? If Earth is tilted, Polaris' path should be in winter 23 degrees away from its path in summer, or not?
15
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4answers
5k views

Jupiter FM - What are practical and inexpensive ways for the amateur detection of signals from Jupiter, especially of the transit of her moons?

What modifications to a standard AM/FM or shortwave radio are needed in order to be able to detect radio-wave signals emitted from Jupiter? Would it be possible to detect the transit of the major ...
2
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0answers
17 views

Recreating Observer Ecliptic Lat/Lon from JPL Horizons using SPICE toolkit

I apologise if this is the wrong place to ask. I am trying to recreate part of the calculations by the JPL Horizons system using SPICE. Specifically the Observer Ecliptic Latitude and Longitudes. I'd ...
20
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2answers
120k 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 the details of Jupiter what was expected. ...
4
votes
1answer
229 views

What's the object in the sky?

Days before, I saw this pic. I don't know what it is. Edit: This pic was taken by a Taoist at an ancient ruins in Mongolia on 2012-07-15 04:12 UTC+8 (day break). He said it looked strange. Edit: I ...
0
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1answer
57 views

calculating stellar visibility

Please could you let me know a (basic) formula for calculating at what time a star would become visible of an evening in clear weather conditions. I presume the formula would involve the stars ...
3
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1answer
58 views

Moon's path as seen from Earth

As observed from the surface of Earth: Will the moon ever repeat the same path (trajectory)? If yes, what is the period of repetition? And also will the moon cover the night sky with its path ...
1
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2answers
58 views

What are some of the best astronomy gatherings in the USA?

I'm part of a local astronomy club but the results from that have been vastly underwhelming with a membership count of around 50-200 active people at any given time. All that being said- I guess my ...
2
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1answer
105 views

Does the Sun twinkle?

Does our solar system have enough bodies in orbit to appear to twinkle to another distant solar system viewed from the side? https://en.wikipedia.org/wiki/List_of_asteroid-discovering_observatories ...
2
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2answers
89 views

Options for first time astrophotography w/ 80/900 refractor?

Recently I bought a telescope and I started to take pictures of my observations. The most basic solution, I'm using a smartphone adapter and my Xiaomi Mi 6 camera to do that but the images (except for ...
3
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1answer
111 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 ...
0
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1answer
114 views

Does weight influence Earth's spin? [closed]

If put enough weight on a particular point on Earth's surface disturbing the balance between hemispheres, is it possible that the Earth's spin could change like an unbalanced spinning top?
23
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2answers
2k views

Where can I find/visualize planets/stars/moons/etc positions?

What resources are available to find the positions of planets, stars, moons, artifical satellites, asteroids, and other heavenly bodies?
4
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2answers
115 views

Scientifically important discoveries with the help of amateurs

I am looking for examples where amateur astronomers in these days contributed sigificantly to important scientifically discoveries. I am aware of one example: Victor Buso from Argentina was lucky ...
1
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1answer
65 views

Are the stars seen at the equator different throughout the year?

If you live on the equator and look up at the night's sky at, say, midnight, would you see a completely different sky on the 1st of January than you would on the 1st of July? I assume you would as ...
8
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1answer
189 views

What's the white glow around this star?

A few days ago, I took a photo of the night sky in the mountains of Georgia with my DSLR. There, I noticed that one single star (in the center of the part of the photo that I added below) looks very ...
0
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1answer
52 views

If the axis of the Earth was through Greenland, what would the north celestial pole be? [closed]

If the axis of the Earth was through Greenland, what would the north celestial pole be?