# Tag Info

13

telescope.com has a quick paragraph on astronomy. Below I summarise the important points with a few of my own suggestions thrown in. Dark & dirty places Set up on grass or dirt, pavements and buildings radiate the heat again at night and the air flow created by this can distort your image. If possible you might be able to make use of a public park. ...

11

Since Andromeda is already visible to the naked eye, to a civilization located at half the distance from the Milky Way, Andromeda would be still be visible. Its total brightness would be four times higher, but since its area would grow by the same factor, its surface brightness would stay constant. The Milky is less bright by a factor of ~2.5, but also ...

9

Planets, if any in that star system, would be visible to the naked eye, the way you can see Mercury, Venus, Mars, Jupiter, Saturn and Uranus in our system. On a virtually empty sky, they would draw that much more attention. Of course, if you had a Moon (or several moons), that would be visible too. Very rarely and briefly, asteroids passing by very close ...

8

The question is not altogether well defined. One needs to specify what wavelength is being considered and at what position in the sky - since a twilight sky has a very significant gradient of sky brightness. A paper by Patat et al. (2006) gives the brightness of the sky in the UBVRI photometric bands, at zenith, with the Sun at a variety of altitudes (...

6

There's a recent study on this, based on satellite and ground observations around the world. According to the paper: The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. And there's a map: The New World Atlas of Artificial Sky Brightness. This is probably the most accurate and up to ...

6

Googling for 'light pollution map' gives a pretty good looking result. Those things usually are created using satellite measurments that are susceptible to scattered light (by measuring the polarity of light) in order to separate direct illumination from actual light pollution. I also suggest you visit a city and then compare the light pollution index on ...

6

You can see the Andromeda galaxy with a naked eye, even with some level of light pollution. So if the star you are asking about would be even closer to Andromeda, you would see at least that galaxy. There are some other galaxies that can be seen from Earth with a naked eye or with binoculars, so sky of such a lonely planet would still have some night lights ...

6

Ok go on Stellarium then hover over the left side of the screen afterwards click on the location and select London, England (City Of London is the original walled city), then go and hover over the left side of the screen and select sky and viewing options and in the sky section and select the air pollution level from location database then it will ...

6

As you probably know, the moon only shines by reflected sunlight and has a very low albedo. Its light is therefore only a tiny fraction of the light of the sun Even the light of the full moon varies, because the moon's slightly elliptical orbit brings it closer to the Earth at perigee than at apogee. Sunlight would light up the sky to about the same extent ...

6

There is hope! You may be able to see some stars through a telescope even though you can't see them with your eye. For extended objects like sky brightness, nebulae, and the Moon and resolved planets, magnification reduces sky brightness, while aperture increases it. For unresolved (point-like) objects like stars and unresolved planets, as long as focus is ...

4

I would recommend the PiNoir Camera. Since it has no IR-filter attached, it's perfectly made for nightly observations. If you need the Raspberry just to calculate Skyglow in general, you could try to collect all light and bundle it to a beam, then measure its intensity. What also came to mind is: When calculating the rating of the night, or a point in the ...

4

Tought to answer, because the amount of airborne dust due to meteor showers and its stability in the upper atmosphere will vary significantly enough. We had many meteor showers, Perseids included, in the past that were a bit of a letdown and didn't produce as many shooting stars as initially predicted, and also the other way around of course. But here's the ...

4

Light pollution occurs because light from the ground refects off atoms in the atmosphere. So you can reduce light pollution either by getting away from light, or getting above the atmosphere. 50%of the atmosphere lies below 5500m, if you can get 5500 m high, you half light pollution. Getting high also improves clarity, and reduces the disturbance caused ...

4

Noctilucent clouds are not a problem for space telescopes because their orbits are always more than 85 km. The Hubble Telescope orbits at about 570 km. Noctilucent clouds are a problem for ground-based telescopes (although only at high latitude sites,> 50$^{\circ}$), especially if you are trying to get accurate photometric brightnesses. However, typically ...

4

It is pretty obvious from a dark sky. Sky and Telescope have a simulation (using stellarium) of the sky with a limiting magnitude of 6.5 (about the limit with excellent eyesight and a very dark sky). The Milky Way is very clear. Light and dark tracks are visible. It is clearly something that every person would know about and be able to see nightly. It is no ...

4

It's a little hard to guess what research can be done there -- Today, Greenwich is close to the worst place on Earth to have an observatory: At sea level, in the light dome of one of the largest cities in the world, in a country famous for its clouds and fogs. The Wikipedia article on the observatory mentions the new telescope and says: In 2018 the Annie ...

4

While light pollution certainly makes things more challenging, there are a number of objects that tend to compete with light pollution well-enough to be enjoyed. I have done astronomy outreach events from urban parks (located in downtown metropolitan areas) where light pollution is extreme. Faint deep-sky objects typically can't be viewed without special ...

3

The answer is yes: dust is highly constrained to the ecliptic plane and so viewing from above the plane would result in less light that needs to be subtracted from observations of the solar corona. The zodiacal light is quite strong in the direction of the sun because the dust strongly scatters in the forward direction. Near the Sun, its surface brightness ...

3

Assuming you mean Bortle class 4, then the Andromeda galaxy (M31) should be a fairly easy object with the naked eye. It won’t be particularly impressive, but rather will look like a hazy blob. On the other hand it is more than 2 million light years distant, so it’s impressive to be able to see it at all.

3

You may be out of luck. If you live pretty much anywhere in the North East, there are very few locations where you can see a truly dark sky. You might be able to get somewhere where you can see the faint glow of the milky way band, but to see a really dark sky, you pretty much have to be out west in the middle of no where. One resource to help you out is to ...

3

I don't have any photos right now, but I think the only photo that really comes close was James K's. The Milky Way looks much like it does in the photos, but with much less magnitude, and virtually no color variation. This is because rods in our eyes allow us to see in dim light, while cones help us differentiate color. If you're in a dark location, in my ...

3

I would agree that transparency is the more important item, but it does depend on what you are observing. Deep sky objects such as clusters, nebulae, and galaxies will benefit from the darker skies by the better transparency. The Sun, Moon, planets and double stars will benefit more from better seeing than better transparency (but my guess is that you are ...

3

Well, light, and the resulting sky glow comes in a lot of different wavelengths, so the first question you need to ask yourself is what range are you looking for? If this project is intended to give someone a good idea as to whether it is worth their while to drag out the telescope on a given night, chances are you only care about human visible wavelengths (...

2

Light pollution does not matter for the Moon. Even transparency doesn't matter that much. What does matter is seeing, a.k.a. air turbulence. It is very rare that an exit pupil smaller than 0.5 mm is useful for anything - perhaps for some tight double stars, but that's about it. So take that as a hard lower limit. In terms of a "soft" limit, it depends. If ...

2

It depends where you are standing, which altitude and longitude. The nearest the equator and the higher altitude, the clearer the stars are. Here's a bunch of pictures by a guy called Cohen who alledgedly calculates his exposure time. I can confirm that the countryside in France, the sky is looks like that when your eyes are used to the dark. At Lattitude ...

2

I saw it once although I was at the perifery of a "rather big" industrial town, but it was very cold and clean. At first I was even scared of some chemiluminescent pollution! It was far from the spectacular display of photographs or from what one can see as reported in the other answers above but nevertheless breathtaking. Two arched stripes of white ...

2

You might try https://clearoutside.com/forecast/50.7/-3.52 It gives weather and visibility among other things. They have an app for iPhone and android. Advertises site was developed by astronomers.

2

The darker the better. There are meteors of different brightnesses in the Perseid shower, including some fireballs that can be seen in any (cloudless) sky. But many of the meteors are dimmer, and the quoted rate of 60 per hour assumes dark skies. As there is no moon tonight, you would benefit if you can get to a dark sky location. If you can see the ...

2

Wherever you have a dark place, you can see the Milky Way. Anywhere in the countryside, far from large cities might work. And it doesn't need to be a very far away - a few km may do the work, specially if there are some hills in between.

1

As JohnHoltz said, only the OP of the linked question can answer definitively. Chances are, they are referring to the Bortle scale, as that is the most common one you will hear of. There is also the NELM method (Naked Eye Limiting Magnitude) that classes the darkness of the sky by the faintest star you can see with the naked eye. There is also the ...

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