# All Questions

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### Can't find Cassiopias Schedar or Caph in Tycho-2 catalog supplement 1

I'm trying to locate three stars inside Cassiopeia, gam cas, Schedar, and Caph. I have found gamma Cas inside the Tycho-2 catalog supp1.dat file, however when I look for Schedar or Caph I have no luck....
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### Black hole at Galactic Center of the Milky way and Bar of stars?

The Milky Way is a barred spiral galaxy, with a supermassive black hole at its center. Here As it is a barred spiral galaxy, it has a central bar-shaped structure composed of stars.Here So my ...
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### Can there be elliptical rings around a planet?

The rings of Saturn and Jupiter are circular. Orbits can be elliptical, so can rings be elliptical?
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### Is the Sun really a medium size star?

It is often said that the Sun is a medium size, or even dim star. Is this true? According to this list of stars within 21 light years, there are, out of the closest 121 stars, only six brighter than ...
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### Why are tides biggest during the equinoxes?

I've read that during the equinoxes, tides are at their maximum. Shouldn't this only apply to latitudes near the equator? I mean, when the solar declination is near to 0º and we have a full or new ...
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### Do galaxies change shape and size over time?

Galaxies come in different shapes and sizes. What factors determine the shape and size of a galaxy, and how can these change over time?
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### How are heavier elements such as carbon and silicon distributed within the Sun?

In a previous question I asked about the source of carbon and silicate dust that Solar Probe Plus will encounter in its close flyby of the Sun. It seems likely that most sources would include infall ...
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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 ...
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### Observed data: Why so many MPECs about TNOs lately?

The Minor Planet Electronic Circulars (MPECs) for July 15 through July 18 reported an unusually high number of re-observations of known trans-Neptunian objects (TNOs). These were found in the Pan-...
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### Why does the Moon appear gray when passing between the Sun and the Earth?

Shouldn't the Moon appear as bright as a full Moon seen at midnight from Earth? The photo was taken by DSCOVR at Lagrange point 1. In the picture, The Moon appears dark gray. Of course the Earth ...
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### Pinhole Projector: Can I use a specific solar optical eye piece to focus the Transit of Mercury?

The title pretty much explains this one. Can I use a specific solar optical eye piece, or other optical device, in conjunction with the pinhole projector method to focus the Transit of Mercury? ...
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### How does Astronomy, amateur and professional, contribute to humanity and a better world? [migrated]

I think this is a good question to ask. There are possibly many aspects to this question. Astronomy and seeking knowledge has lead to the development of space probes, space science, development of ...
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### Is this a real picture of the moon?

I found this picture and I am really wondering if it is possible for the moon to get as close to the earth as this picture shows? ( Super moon above Rio De Janeiro)
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### Does Earth transit look like a black dot surrounded by red light?

As we know, lunar eclipse appear red, if we can see Earth transit from Mars, does it look like a black dot surrounded by red light on the sun?
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### Best format for analyzing and comparing coordinates across multiple tables

First coding project so if I am asking something wrong or asking too much please let me know. ANY help or advice would be greatly appreciated, including how to better word this question if necessary. ...
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### Why can we trust Hubble Time if the rate of expansion is not constant?

The age of the Universe can be estimated from taking the inverse of the Hubble constant: $t_\text{universe} = 1/H_0 =d/v.$ It seems to me this method assumes that any given galaxy has been receding ...
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### Refraction by Saturn's atmosphere - how dense is it here?

This tweet from CassiniSaturn shows an image of Saturn's rings being optically distorted by the dense atmosphere. It is explained more fully on this page and is available here. The refraction is ...
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### Is the radius used in the formula for the escape velocity the average radius of the celestial object or the radius at the starting location?

I learnt that the escape velocity is given by $$v_e = \sqrt{\frac{2GM}{r}}$$ Say I want to launch a rocket from the earth into space and want to calculate the escape velocity $v_e$ (I guess without ...
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### What is the origin of the dust near the sun?

In this question I asked about the Solar Probe Plus mission. Reading a 2008 report I saw that there is an elevated exposure to high velocity dust near the sun. I understand the high velocity, anything ...
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### How do you estimate the error on the height/width of a Gaussian?

I'm trying to fit Gaussians to several lines in a spectrum that I have. Some of them overlap with one another, causing the fitting program that I'm using to not be able to give reasonable estimates ...
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### Will Gaia detect inactive neutron stars?

Will the astrometric precision of the Gaia space telescope be able to detect the gravitational influence of cold old solitary neutron stars on the movements of stars? At least in a statistical sense ...
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### Parts of the Universe Shows Fewer Named Stars [duplicate]

I'm becoming interested in the currently identified stars in the universe. There is a wide swath where much fewer named stars are shown. Why is this? The image below is a mollweide projection of the ...
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### Will Saturn's Moons be destroyed?

I heard that Saturn has 62 moons with confirmed orbits, 53 of which have names and only 13 of which have diameters larger than 50 kilometers. Some come within 1km of each other. How do these moons ...
376 views

### What happens to the information on the event horizons of two merging black holes?

What happens to the hairiness/information on the horizons of two black holes if they collide? After Hawkin the information of the matter which has fallen into the blackhole is encoded on the surface ...
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### What is the frequency distribution for luminosity classes in the Milky Way Galaxy?

I'm working on a game concept that does some mild simulation of realistic stellar classes and luminosities. In particular, I'd like to roughly model the general frequencies of the classes and ...
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### Is the sun really white? [on hold]

"If you could travel into space and look at the Sun without going blind, you'd find that it's actually white, and not yellow" "White light is composed of all the visible colors in the electromagnetic ...
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### Weird light in the sky, curious as to what it is [on hold]

One night (a couple days ago) I looked out my bedroom window and saw a red light. It was fairly big but obviously not close to the window. It was moving, back and fourth between the distance of a ...
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### Current communication delay to mars [migrated]

I'm not sure if I should ask this question here or on the Space Exploration Stack Exchange. If I'm on the wrong network here, please let me know. I read that the communication delay between earth and ...
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### Using SkyChoord to read in multiple coordinates.

so I recently wrote a basic code to analyze the distance between two points which are stored in two separate excel files. Now that I have that code working its time to apply the legitimate use and use ...
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### Jupiter, Saturn, Uranus, Neptune system GM

I'm modelling the solar system. I'm using data from Nasa. To do this I'm using the barycenter of the planets Jupiter, Saturn, Uranus, Neptune. However the website fails to give the Gravitational ...
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### How far away is the nearest compact star remnant likely to be?

Neutron stars and black holes are hard to detect when they are solitary, and there seems to be big uncertainties about how common they are. White dwarfs are much easier to detect and the nearest one ...
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### Statistically, what would the average distance of the closest black hole be?

The closest confirmed black hole is several thousand light years away from earth. Our galaxy has about 100 billion stars. I didn't find any reliable information on the black hole count of ratio versus ...
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### More than 67 Jovian moons?

Wikipedia says that there are now 67 known moons of Jupiter. It got me wondering: is it really possible in our day and age that there are more, but we haven't observed them yet? On the other hand, ...
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### Is extraterrestrial mining more difficult or impractical for bodies without plate tectonics?

This article talks about the possibility of mining Uranium on the moon. Since the Moon lacks the geological forces that have created veins of concentrated minerals on Earth, would extraterrestrial ...
106 views

### Blackhole Finding Techniques

I know of two methods for finding exoplanets: the transit method and the radial velocity method. These two methods work as follows: Transit: we observe stars and watch for when a planet obstructs ...
130 views

### What is the temperature of the solar atmosphere (the corona) and how is it measured?

The temperature of the Sun's atmosphere, also referred to as the solar corona, is known to be hot even hotter than the Sun's surface. What is its temperature and how is it measured? How does it ...
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### Cluster of fast moving stars

We live in NW Tasmania in a country town and tonight out walking I pointed out a long cluster of stars to my sister as they made an unusual shape but then we realised they were moving really fast - we ...
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### Bright two moving lights on the night sky [closed]

About a month ago, I was out with my friends, It was midnight, and We were watching a bright dot in the sky. It was shining more than the stars. (It is there everyday, cca. 3 years, before that it ...
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### Is remote measurement of isotope ratios possible, or must a sample be aquired

Is it possible to measure to measure isotopic abundance of remote astronomical objects - ie measurement without having a sample to feed into a mass spectrometer? Do different isotopes show any ...
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### Why celestial objects appear brighter in the night sky than in photographs from closer proximity?

The moon, for example, appears very bright in the night sky, but quite dark from photographs on/near its surface. Similarly, Mars and Venus appear as bright dots in the sky but in closer photographs ...
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### Is it possible that a star system ejects an object out of the galaxy?

I know it is possible that a star system ejects a planet out of the star system and the planets becomes rogue planets and orbit around the galaxy. Is it also possible that a planet gains enough speed ...
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I was looking for accurate and up-to-date data regarding the advancement of the perihelion of the planets in the Solar System, the only ones I've found so far are at least 90 years old bout I really ...
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### Planets, gem stones and their psychological effect on society [closed]

I have been having a pretty bad events happen to me lately. Any new undertaking turns sour. Situations that seemed to be getting better yesterday suddenly take a turn for the worst. For example I ...
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### Interfacing FORTRAN programs for model atmospheres with IDL or Python

I'm trying to use model atmospheres such as Kurucz or MARCS for the first time personally and I'm wondering if it is better to wrap it with IDL or Python in terms of writing the code, and getting the ...
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### Why did the Big Dipper form? [closed]

There is an asterism comprising 7 stars, known as Saptarishi mandalam, but better known to the Western world as the Big Dipper. It gets its name from the seven rishis. Why did this asterism form, why ...
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### Do primary mirrors in large observatories undergo regular removal and re-coating of the aluminum? Why?

Performance of astronomical mirrors that are exposed to the environment for long periods of time can experience a slow degradation of performance. They usually need to receive some kind of regular ...
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### Universal point for sky observation

Is there a place on Earth, where polar axis lies on the horizont and heaven equator is in zenit? If it exists, can I, in theory, see all the constelations available worldwide this night?
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### How often is a blue moon?

A blue moon is two full moons in the same month. How many times will a blue moon occur in the average lifetime of say 70 years?