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Questions tagged [amateur-observing]

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

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42 votes
2 answers
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Where can I find the positions of the planets, stars, moons, artificial satellites, etc. and visualize them?

What resources are available to find the positions of planets, stars, moons, artificial satellites, asteroids, and other heavenly bodies?
user avatar
27 votes
2 answers
156k views

How much magnification is needed to see the 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. ...
Tanmoy Banerjee's user avatar
21 votes
2 answers
1k views

How will Starlink affect observational astronomy?

I have recently found that people around the world have been posting observations of a line of moving objects in the sky which is very likely to be a part of Starlink satellite constellation, such ...
Leo Liu's user avatar
  • 381
7 votes
2 answers
708 views

How will planets behave in the night sky as seen by Mars colonists?

Certainly among the first colonists on Mars there will be a few people interested in Astronomy enough to enjoy the night sky. For them, familliar Mars will be missing and there will be a new, ...
uhoh's user avatar
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25 votes
4 answers
4k 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 ...
uhoh's user avatar
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3 votes
2 answers
237 views

When would we detect a tiny meter size natural satellite 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? I ...
Mario Krenn's user avatar
1 vote
2 answers
90 views

Binocular highlights from Tasmania next few weeks?

My friends are visiting southern Australia and Tasmania for the next few weeks. I am lobbying them to bring my Nikon 8x42 binoculars so they can appreciate the Milky Way and possibly see a few other ...
uhoh's user avatar
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13 votes
2 answers
5k views

What is that donut-shaped object I see in my telescope? [duplicate]

I was looking through my telescope for the first time and came across this weird star. I think its a celestial donut but im not sure.
Mani S's user avatar
  • 149
6 votes
1 answer
512 views

Requirements to resolve position of Jovian Whistlers up to magnitude of Red Spot with amateur radio equipment?

Can I sense a bright star pointing an eight foot antenna towards it? is a while ago, but the discussion about this question I found very interesting. Please forgive me that I am not an expert in ...
B--rian's user avatar
  • 5,616
5 votes
1 answer
562 views

How bright is the Crab Pulsar's 30 Hz modulation in visible light? What color is it?

This answer to Has great eyesight been necessary for astronomers? mentions Astronomer Jocelyn Bell Burnell's recounting of a likely first visual observation of a pulsar. This can be found for example ...
uhoh's user avatar
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22 votes
4 answers
6k views

How would the night sky look from inside a globular cluster?

When the weather is clear, we can look at the stars. And we normally would see several thousands of them, they all being more than a $\textrm{pc}$ away from us. Now, there are globular clusters, ...
Alexey Bobrick's user avatar
14 votes
1 answer
2k views

Apparent size of M31

I am trying to understand something I read on wikipedia about M31. Wikipedia says that M31 appears more than six times as wide as the full Moon. But I remember that when I watched it naked eye it ...
Mario Stefanutti's user avatar
11 votes
1 answer
2k views

How big a dish do I need for radio astronomy?

I've recently become interested in the idea of building my own small-scale radio telescope. A quick online search finds a few instructions on how to build this using a satellite dish. These suggest a ...
Beta Decay's user avatar
9 votes
3 answers
14k views

Why haven't I seen the Moon?

It has been some time since I've seen the Moon. What are the conditions that might affect whether or not the Moon is visible within a 24-hour period? Please take into consideration any notable ...
Andrew lloyd's user avatar
8 votes
1 answer
315 views

Does this amateur observation hold a record even including robotic searches for supernovae?

The new paper in Nature A surge of light at the birth of a supernova (doi:10.1038/nature25151) describes the fortuitous capture of a supernova "Shock Breakout" - the earliest rise in brightness of a ...
uhoh's user avatar
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7 votes
3 answers
25k views

Why does Venus flicker?

I was watching Venus with the naked eye yesterday at about 7 pm and I noticed that it was flickering, almost like a star. I have always learned that planets don't flicker to the naked eye, only stars ...
TomCho's user avatar
  • 390
7 votes
1 answer
944 views

Why don't we use amateur astronomers' telescopes to create a huge interferometer?

Some telescopes in space have been proposed to function as an interferometer. Being placed several hundreds or thousands of kilometers apart they could actual image exoplanets directly. To my ...
8192K's user avatar
  • 173
5 votes
1 answer
485 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?
Anthony McCloskey's user avatar
5 votes
4 answers
596 views

How can Mercury's sodium tail be imaged?

I recently learned that Mercury has a sodium tail. Can this sodium tail be imaged with a ground based telescope? Is so, what is the minimum setup required to be able to take a picture of it? Do you ...
usernumber's user avatar
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4 votes
2 answers
2k views

Why does this large Newtonian telescope's front cover have two or three holes in it?

The Michael Bernardo video How to use an Equatorial Mount for Beginners shows a large Newtonian telescope on an equatorial mount. The cover of the telescope's large aperture shows what looks like ...
uhoh's user avatar
  • 30.8k
3 votes
2 answers
547 views

Astromaster Celestron 130 EQ

I brought a new Astromaster 130 EQ and collimated it using a laser. However, whenever I try to observe moon I get a perfect picture but with other planets I see only a bright glowing ball which ...
Hukambeer's user avatar
2 votes
1 answer
160 views

Automated (and hopefully free) systems I can subscribe to sending email or SMS text message when the T Coronae Borealis Nova becomes visible?

My earlier question about predicted potentially observable events Has a gravitational microlensing event ever been predicted? If so, has it been observed? is limited to microlensing. Now I have just ...
uhoh's user avatar
  • 30.8k
1 vote
1 answer
495 views

Can an average person see stars from the bottom of a well or through cardboard tubes? Definitive answer required!

A debate about seeing stars or planet during the day below this answer to the Aviation SE question At what altitude might a pilot be able to see at least the brightest stars during the day? seems ...
uhoh's user avatar
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18 votes
4 answers
7k 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 ...
user avatar
16 votes
3 answers
2k views

Was lunar libration first observed or first predicted? In either case, who was the responsible party?

How old is the idea of the far side of the Moon? got me thinking that as soon as we see the moon librate we have to come to terms with there being even more of it we can't see. The Moon's libration is ...
uhoh's user avatar
  • 30.8k
10 votes
1 answer
375 views

Can one build a distributed radio telescope?

I understand some radio telescopes are built as arrays of receivers. Could one build an array from a heterogeneous set of receivers in scattered locations? Suppose a large number of persons each ...
Joe Cooper's user avatar
9 votes
2 answers
3k views

What kind of things I could "see" with an amateur radio telescope?

There are apparently not many reasonably priced radio telescopes available for the amateur users. I only could find a SPIDER 230C 2.3 meter diameter compact radio telescope, which costs ~10 k€. ...
mmh's user avatar
  • 404
8 votes
2 answers
587 views

How could I see Andromeda as large as in this picture?

In this question an image is shown (repeated below) which gives an idea of the "true" angular extent of the Andromeda galaxy in our sky. When I see Andromeda it is usually a bit of a smudge ...
ProfRob's user avatar
  • 152k
7 votes
1 answer
973 views

What radio frequency ranges are most beneficial for astronomy?

I cannot get the idea of citizen radio astronomy out of my head, and choosing an antenna (design) heavily depends on the desired frequency range. The Arecibo telescope as my gold standard operated 300 ...
B--rian's user avatar
  • 5,616
7 votes
2 answers
37k 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 ...
Ceribia's user avatar
  • 261
7 votes
3 answers
1k views

Eyepiece diameter for small focal length planetary viewing on a large dobsonian?

I have a 12" dobsonian with a 1500mm focal length and want to do some higher magnification planetary viewing. Currently my highest magnification is ~80x via my 19mm eyepiece (calculated here), but I ...
Cory Klein's user avatar
6 votes
1 answer
378 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 ...
Sir Cornflakes's user avatar
6 votes
0 answers
335 views

What would go into the design of a simple sky quality meter, used to measure night sky brightness?

@MCG's answer mentions several methods to classify night sky quality or brightness, and goes on to say: Additionally, you could always purchase a SQM (Sky quality meter) which is a small, portable ...
uhoh's user avatar
  • 30.8k
6 votes
0 answers
240 views

Viewing "Diamond Fuji"

Diamond Fuji is a phenomenon in which the (typically) setting sun is positioned directly atop Mt Fuji. Some relatively detailed predictions for viewing times at a nearby park are available here. I ...
kyle's user avatar
  • 161
5 votes
3 answers
641 views

What is it about the layout of the three gratings in a Bahtinov mask that makes its indicate focus in this way?

The question Lucky imaging with Celestron 14 - is this result reasonable? includes a beautiful example of a focus test using a Bahtinov mask and the image below from Deep Sky Watch's Home Made ...
uhoh's user avatar
  • 30.8k
4 votes
1 answer
855 views

Under what situations can an aperture mask improve the resolution of a small/medium amateur telescope? Is this demonstrable mathematically?

@antlersoft's answer describes some of the challenges to seeing any details in the small disk of Mars in small amateur telescopes. In the case of reflecting telescopes, it mentions the use of either ...
uhoh's user avatar
  • 30.8k
4 votes
0 answers
67 views

Is it possible to use something besides emulsion to directly record the image of a nighttime object using a telescope?

The following questions have got me thinking. Is it possible to use Photolithography for telescope image sensor? Fresnel lenses for a makeshift Galilei telescope? Has anyone ever tried to make a ...
uhoh's user avatar
  • 30.8k
4 votes
1 answer
374 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 ...
uhoh's user avatar
  • 30.8k
3 votes
0 answers
98 views

Unknown moving light in sky [duplicate]

On July 13, 2018, while camping in Southwest Oregon, a bright light appeared in the sky at sunset. It was much brighter than Jupiter, also visible. It was moving slowly, west to east. I estimate it ...
Randy Pearce's user avatar
3 votes
1 answer
474 views

Has a near earth object in heliocentric orbit ever been bright enough to be visible to the unaided eye?

The question Can we see asteroid 1998 OR2 with unaided eye? got me thinking. Space.com's Vesta: Facts About the Brightest Asteroid says: Vesta is the second most massive body in the asteroid belt, ...
uhoh's user avatar
  • 30.8k
3 votes
1 answer
467 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. ...
uhoh's user avatar
  • 30.8k
3 votes
1 answer
371 views

Not getting quality images in telescope

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 eyepiece), a 3x and 1.5x ...
Kavin Ishwaran's user avatar
2 votes
1 answer
443 views

What exactly is a Hamiltonian telescope? Is this one?

This comment on the current answer to Why is this telescope so short? How hard is it to make such a fast primary? says In this forum topic Borisov appears to call it an f/1.5 Hamiltonian. Wikipedia'...
uhoh's user avatar
  • 30.8k
2 votes
1 answer
119 views

Are there home-brew photometers for amateur observing of variable stars and are they widely used?

Comments on Why do these photometric observations of Betelgeuse look “quantized” in 0.1 magnitude steps? suggest that these are visual estimates, mostly (but not all) to 0.1 magnitude resolution. Are ...
uhoh's user avatar
  • 30.8k
2 votes
1 answer
1k views

How to calculate B-V colour index value percentage difference

I need to calculate a percentage difference of a B-V colour index between its estimated and actual value. So I tried doing this by difference between values/actual value x 100. However as B-V values ...
Edwin Shepherd's user avatar
1 vote
1 answer
2k views

Choosing an eyepiece for planet viewing

I have a Celestron Astromaster 130EQ which came with a 10mm and 20mm lens. I can not see mars, Jupiter, or Saturn as expected, I only see white dots. What lens should I buy to view these planets.
stan greene's user avatar
48 votes
3 answers
15k 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?
Guest55's user avatar
  • 379
42 votes
2 answers
1k views

How do I calculate the inclination of an object with an amateur telescope?

Suppose I would like to calculate the inclination of a satellite from the ecliptic. Would it be possible to do this with an amateur telescope? How would I go about doing so? Note: A good answer ...
called2voyage's user avatar
  • 6,322
26 votes
4 answers
8k views

What would happen if someone had a telescope and watched Betelgeuse when it goes supernova?

Would that person go blind? Neutrino detectors and the abundance of Neutrinos would detect the upcoming visible show about 3 hours before any visible signs, so there would be time to point certain ...
userLTK's user avatar
  • 24k
22 votes
2 answers
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 ...
Edd's user avatar
  • 229