1
vote
1answer
31 views

Is the conversion from proto-star to main sequence an event or a process?

When a proto-star becomes a main sequence star, is that something that happens in an instant when a certain threshold is met, or is it a process that takes a few thousand/million years?
2
votes
1answer
32 views

Do all stars have the potential to have life supporting planets?

Regardless of how big or small, how hot or cold, do all stars have a goldilocks zone, and if so, could any given planet in this zone (with the right configuration) support life?
2
votes
1answer
30 views

How much light does Jupiter project onto the surface of Ganymede?

I suppose the answer would be a range as the Jupiter-facing side of Ganymede passed from Jupiter's light side to its shadow side. I'd also like to know how much light the sun projects onto the surface ...
0
votes
1answer
19 views

Help w/ Hubble's Law + Doppler Effect.

I had a question about the following chart. What mathematical observation or equation could be made about the data given in respect to the doppler effect? I'm confused if this means that planets are ...
1
vote
1answer
24 views

How do astronomers estimate the total mass of dust in clouds and galaxies?

As I understand it astronomers estimate the mass of stars by studying the orbits of their companions (other stars or planets). This helps them to derive relationships between the luminosities and ...
0
votes
1answer
34 views

Better than Earth habitability

Earth undoubtly has very good conditions for supporting life. Although it is expected that many other planets on the outer space have conditions at least as good as Earth, the vast majority doesn't, ...
1
vote
1answer
239 views

Mass distribution in the early universe

The latest big quasar find at ~12.8 bn LJ with an estimated mass of 12 bn M☉ (see e.g. http://www.newscientist.com/article/mg22530104.000-ancient-black-hole-had-an-inexplicable-growth-spurt.html) puts ...
2
votes
1answer
37 views

How can a galaxy in-between our view and the galaxy behind it have a 'lensing effect'?

In this article, the author writes: This galaxy is so distant that it would have been invisible without the gravitational lensing effects of a large galaxy cluster called Abell 1689, located ...
-2
votes
0answers
12 views

Finding Latitude and longitude [on hold]

How do I determine the my location, lat and long, from the date, September 21st, the time of sunrise 6:09, the time of sunrise the previous day in LA 6:41, and an atlas???
2
votes
2answers
466 views

What's the mass of the interstellar neighborhood of the Sun?

What's approximatively the mass of the interstellar neighborhood of the Sun ? (for example the neighborhood of radius 50 light-years). Remark: The mass of the observable matter should be completed ...
0
votes
1answer
32 views

Free source of printable star charts in the format of the Millennium Star Atlas?

I've been looking for sources of printable electronic star charts - there seem to be many different ones available, either as part of planetarium software or just plain charting packages. But there's ...
4
votes
1answer
55 views

What are the cloud-like blobs in the Martian southern hemisphere?

In a very recent edition of New Scientist, an article Mystery cloud-like blobs over Mars baffle astronomers (16 Feb, 2015), detailed that on 12 March 2012, amateur astronomers around the world ...
0
votes
2answers
31 views

Nebula and galaxies using 70mm scope

Telescope: Orion 09843 SpaceProbe 3,3 inch aperture(76mm), 700mm focal length, eyepieces - 25mm and 10mm focal lengths. Please tell me whether it is possible to see nebula and galaxies.
-1
votes
3answers
88 views

Does the Sun turn around a big star?

The moon turns around the Earth. The Earth turns around the Sun. Does the Sun turn around a big star? If so, does this big star turn around a very big star? ... etc ... What are all the intermediate ...
0
votes
1answer
23 views

Internal heat and differentiation

I was reading an article on planetary differentiation, and apparently internal heat producction plays a mojor role. There are several sources of such heat described, such as tidal heat, radiogenic ...
0
votes
0answers
29 views

Exoplanet Temperature Calculations

I was given an exoplanet similar in size and distance to host star to our own earth. It's orbiting a star with luminosity six times our sun, the greenhouse coefficient 0.3, bond albedo 0.3. I need to ...
3
votes
1answer
54 views

How can we tell that a short-period binary is tidally locked?

Observationally, how can this be established? What is known theoretically about the process? Are there any reference papers to read?
0
votes
0answers
40 views

How do I soundproof a Meade ETX-90 telescope?

I'd like to start using my Meade ETX-90 this summer in my backyard, but I'm worried that my neighbors will start complaining due to high noise this telescope makes when operating. How do I soundproof ...
0
votes
0answers
7 views

begining research in astronomy/astrophysics - how to go about [migrated]

I am a (beginner) researcher in the area of Turbulence, Applied Mathematics and Hydrology. I really want (for personal reasons) to start doing some research in the field of Astrophysics/Astronomy but ...
0
votes
1answer
52 views

When will a day on Earth & Mars be the same length?

I read on Wikipedia that: As on Earth, the period of rotation of Mars (the length of its day) is slowing down. However, this effect is three orders of magnitude smaller than on Earth because the ...
-1
votes
2answers
41 views
3
votes
2answers
137 views

Is there any man-made satellite orbiting our moon?

I am just wondering whether any man-made satellites are currently orbiting our Moon. If there is one, would I be able to see it using my telescope?
-3
votes
0answers
30 views

Radius and velocity of Earth's orbit around the Sun [closed]

How do you find the radius and velocity of Earth's orbit around the Sun?
0
votes
1answer
99 views

When we see the Sun, do we actually see its past?

The Sun's rays hit our eyes around 8 minutes after they are emitted from the Sun. Does this mean that the Sun that we see is always the Sun as it was some 8 minutes before? I strongly think this must ...
3
votes
3answers
130 views

Is gravitational energy released when a body contracts?

Kelvin stated that gravitational energy released due to contraction was responsible for the energy radiated in the stars. Although the theory was wrong, was the assumption practically right? If it's ...
1
vote
3answers
94 views

Temperature of the Sun's rays

What is the temperature of the light that leaves the Sun towards the Earth and does it cool down during it's journey here ? If it doesn't cool down then how come it isn't frying the Earth ? Is it our ...
-5
votes
0answers
46 views

overlapping observable universes [on hold]

From Wikipedia: The observable universe consists of the galaxies and other matter that can, in principle, be observed from Earth at the present time because light and other signals from these ...
-2
votes
0answers
39 views

Does the Multiverse mean that all the universes are related somehow? How would that work? [closed]

The Multiverse means that there is a multitude of universes. But does it also mean that if you do something in this universe, the same thing will happen in another universe just in a slightly ...
-3
votes
0answers
30 views

How are black and white holes formed? [duplicate]

Are they rips in the space-time continuum or what?
3
votes
1answer
45 views

Is the SOI a spherical region or a oblate-spheroid-shaped region?

The Wikipedia article on Sphere of influence states that: "A sphere of influence (SOI) in astrodynamics and astronomy is the oblate-spheroid-shaped region around a celestial body where the ...
1
vote
1answer
34 views

Enhanced Star-Gazing with Special Glasses

I watched a video yesterday on how telescopes not only magnify images but also increase the amount of light entering into your eye, allowing you to see things not normally visible with naked eye. ...
0
votes
2answers
78 views

What's the relationship between Moon phase and the Milky Way visibility?

I've been using an IOS app to predict visibility of the Milky Way. I'm planning a trip to capture the Milky Way on 9th March 2015, but the app shows the visibility will be very weak on that date. ...
1
vote
0answers
58 views

Fourier Transform of Galaxy Images

I'm working on detecting optically overlapping galaxies for future astronomical surveys. I'm looking into feature extraction for HST images and have been computing the fourier transform of images in ...
0
votes
2answers
46 views

Is Blue Shift just as provable as Red Shift?

I've heard a lot about red shift and it sounds pretty legit. But it made it sound as if blue shift was a lot less likely. Can anyone help me out?
1
vote
1answer
20 views

Relationship between temperature of nebula and size of star

I was wondering, in the process of star formation, does the temperature of the nebula that produces a star play a role in the size of that star? I mean, it's only logical that the size would depend on ...
-1
votes
0answers
38 views

Is it a satellite [closed]

I'm relatively new to amateur observing, and I recently got to use my Celestron mid-level computerized scope (Nexstar 127slt) in a rural area. On two of the nights it was pointing at different places ...
2
votes
1answer
141 views

How bright was Scholz when is passed near the Sun 70,000 years ago?

I just read that a star called Scholz passed only 0.8 years-light away from us 70,000 years ago. It is a red dwarf. I don´t know how bright it was in the night sky. Does someone know how bright it ...
-2
votes
1answer
74 views

Why would a star’s position in the sky change relative to another star right next to it? [closed]

I'm curious about stars and I am wondering why a star would change its position in the sky due to another star right next to it?
-5
votes
1answer
65 views

Why are a few things in our universe named after chocolate? [closed]

Like the title says, why are a few things in our universe named after chocolate? For example, there are the Milky Way, galaxy and Mars. Is there a reason for this or not? Or is it that the ...
-1
votes
1answer
24 views

Could a magnetars magnetic field have saved Mars atmosphere?

Just wondering: if a magnetar was close enough to Mars would it have saved its atmosphere by protecting it from solar radiation? I was wondering this because Earth protects us via a magnetic field; ...
-3
votes
2answers
60 views

How dense would planet earth have to be to have the same gravity as Jupiter?

I was reading this question about how small could a planet be while having earth-like gravitational pull. This got me thinking, how dense would planet Earth have ...
0
votes
2answers
63 views

Can Magnetars destroy planets?

Magnetars are the most magnetic things in our universe. Because of how powerful their magnetic fields are, they could split every single atom apart from each other in our body. Because of this could ...
1
vote
1answer
183 views

What happens to a white dwarf past the Chandrasekhar limit?

This is a multiple choice question I had trouble with on an exam. Will a white dwarf that has had too much mass piled on top of it a) undergo a thermonuclear flash and explode in a type IA supernova ...
0
votes
1answer
35 views

Telescope size to detect Ceres (Newtonian)

What is the minimum size telescope required to enable clear visual detection of Ceres?
1
vote
1answer
29 views

How to view Jupiter with 4.5" Newtonian Reflector

I have a 4.5" Newtonian Reflector and I took a look at Jupiter the other night. I was able to get a reasonably sharp view of it and see a number of it's moons, but I was unable to see any surface ...
0
votes
1answer
65 views

Shouldn't all moon orbits be inherently unstable?

A hypothetical simulation starts with a planet called Earth in a perfectly circular orbit around a star called Sol. There is also a moon called Luna in a perfectly circular orbit around Earth. ...
1
vote
1answer
79 views

Could a close passing star be captured by the Sun's gravity?

Earlier I read an article here stating that a binary pair of stars passed within 0.8 light years from the sun. That made we wonder why the stars weren't captured by the Sun's gravity since the sun's ...
0
votes
3answers
99 views

Does the orbital variation in planetary gravity affect the Sun's corona

Dimitris (see below) argues that the syzygies of the Earth and Venus and those of Mercury, Earth and Jupiter distort the Sun's corona, which in some way affects climate on the scale of hundreds of ...
2
votes
2answers
62 views

Would a killer asteroid shattered into thousands of pieces produce the same devastation?

If we blow up a global killer (in the 3 - 20km range) days before impact into enough pieces that none of the them exceeds, let's say, a 30m diameter and the impact pattern is dispersed over most of ...
1
vote
3answers
93 views

Can planets inside the Earth's orbit around the Sun appear to undergo retrograde motion?

Retrograde motion is: The apparent motion of the planets when they appear to move backward (from east to west) from the direction that they move ordinarily with respect to the stars. Can planets ...

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