All Questions

3
votes
0answers
39 views

Can wavefront distortion from gravitational microlensing limit resolution of absurdly large aperture telescopes?

This is a theoretical question. This answer to the question If we had the right technology could we see a distant star in detail? (presumably space-based) primarily addresses the scaling of ...
1
vote
0answers
35 views

How to decide which part of the data is analyzed? [closed]

I need to get the X-ray light curve of Classical Nova V1494 Aquilae (1999 No. 2) in Outburst. It is done long time ago, but I need to this by myself. While reading the papaer about the V1494 Aquilae, ...
4
votes
0answers
105 views

Is Optical VLBI theoretically feasible? If not why not?

There are plenty of optical interferometers in use with baselines of up to maybe 1km. As far as I can find out, they all work by directly collecting the light at all the telescopes, using mirrors to ...
6
votes
1answer
187 views

If we had the right technology could we see a distant star in detail?

If, for instance, Hubble's camera was a 10^300 times better could it see a distant star in details or is there a limit to the amount of light that reaches the earth's orbit or perhaps does the light ...
6
votes
2answers
195 views

Strange speck of light in the picture sequence of the approach to 2014 Mu69 (Ultima Thule)

In the picture sequence which was taken by New Horizons during the approach to Ultima Thule on the 3rd of Dec there can be seen a speck of light in the lower left corner, not as bright as 2014 MU69 ...
3
votes
1answer
106 views

Will the SKA's total bandwidth still exceed the Earth's internet's bandwidth?

In the early 2010's there were many popular articles that said that the total bandwidth of the the Square Kilometer Array's optical fiber network for raw data from each dish would be larger than the ...
1
vote
0answers
35 views

Could Ganymede's aurora be seen with the naked eye?

If one was orbiting in the Jovian system, as depicted in this artist conception, could the aurora be seen unassisted? Hubblesite-Illustration Credit: NASA, ESA, and G. Bacon (STScI)
8
votes
6answers
338 views

Are there other proofs of the expanding universe apart from the redshift?

The theory of the expanding universe is so widely accepted, that the redshift is sometimes used as a measure of distance to far away galaxies. But is it still possible that the redshift is caused by ...
9
votes
1answer
169 views

Why isn't Ultima Thule spherical, while its two component parts are

The two component parts of the Ultima Thule contact binary are approximately spherical. Why have the same forces that made the two parts spherical when they were separate not made the whole thing ...
2
votes
1answer
78 views

What soviet telescope is this?

A friend has a vintage telescope with a broken lens, I asked him to send me its catalog so I can see if I can buy him a new one, he gave me what looks like a Russian catalog, it seems a soviet ...
1
vote
0answers
21 views

Doppler Spectroscopy - Finding mass of an exoplanet

An astronomer, T observed the spectrum of a distant star X. The spectral lines were observed to have tiny blueshifts and redshifts regularly with a period of 1.27 years. T concluded that the star is ...
0
votes
2answers
62 views

Objection on artificial moon for lighting

Some days ago i read about China's artificial moon mission for lighting cities In my junior classes i was taught the effect of Moon's gravity on tidal waves. According to me this is a very dangerous ...
1
vote
1answer
26 views

What discoveries have come from the DASCH project (Digital Access to a Sky Century @ Harvard)

@astrosnapper's answer to the question Could stellar occultations be used to survey Kuiper belt objects? mentions the TAOS-II project and asteroid occultation measurements (which occur on the ...
2
votes
2answers
58 views

Would the solar corona be visible from the distance of the outer planets?

If the photosphere was blocked, before the sun rises on an airless moon in the outer solar system, would either the inner or outer corona be visible to the naked eye?
5
votes
1answer
115 views

Could stellar occultations be used to survey Kuiper belt objects?

The first hint we had as to the shape of Ultima Thule was via an occultation study using an array of small telescopes. Has anyone investigated the feasibility and effectiveness of conducting a survey ...
1
vote
1answer
65 views

What is the exact meaning of vicinity of Black hole or a disk? the same as inside?

What is the exact meaning of vicinity of Blackhole or a disk? Is this the same as inside the horizon for black holes? If so, why people don't say inside of BH, simply. What is the difference? I use ...
4
votes
0answers
46 views

How open is China in sharing data from the Chang'e 4 mission?

It's really good to see that man (well, machine) has gone back to the moon again. Chang'e 4 is studying potential mantle material from the lunar depths and will be conducting radio astronomy in ...
0
votes
1answer
68 views

76mm reflector vs 70mm refractor? Both are at sale at $200

I'm starting my astronomy hobby and looking for a beginner telescopes to start with. I've searched couple websites and found these 2 within my budget. I know for a fact that refractors gives you ...
8
votes
0answers
46 views

How uniformly is cometary debris distributed along the entire orbit of the comet?

Meteor showers occur when Earth passes through debris shed by a comet (if I get that right). Does this mean that the entire orbit of the comet is strewn with debris? I suppose that the debris follows ...
2
votes
0answers
34 views

Issue translating World Coordinate system to cartesian coordinate

I have two fits images from the WFC3 that I am trying to combine with a C# program. When I try to combine multiple images I don't think the values I am getting for my x/y coordinates (calculated from ...
1
vote
0answers
33 views

How much does being at the perihelion heat Earth up?

The author in this article: https://news.nationalgeographic.com/news/2010/07/100707-aphelion-heat-wave-earth-sun-science-weather-nation/ has explained that positional differences on the orbit is a ...
3
votes
1answer
35 views

Brown dwarf magnetic activity

I have not been able to find an answer to my question through google, and therefore ask it on this medium. Do brown dwarfs have spots and faculae similar to other heavier stars?
3
votes
1answer
97 views

How to send information from the far side of the moon to Earth

Chang-E has just sent a shot after landing on the far side of the moon. It looks tricky, how can a device send information from a place that is oriented opposed to Earth?
2
votes
1answer
38 views

What are some formulas that are associated with the Schmidt corrector?

I want to fully understand how an SCT works. Thus, I figured out I can use some formulas that describe how an incident ray that is parallel with the axis would act after refracting off a Schmidt plate....
1
vote
2answers
54 views

Calculation of Eccentricity of orbit from velocity and radius

For a school project I am making a gravitational computer model. As I want to Milankovitch cycles, I need to calculate the eccentricity of an orbit after the model has completed its simulation. I ...
4
votes
0answers
49 views

Does the orbital decay of Triton affect Neptune's rotation?

Just a quick question regarding Neptune. Because Phobos is spiraling in towards Mars, Mars' rotation speeds up. Does the same thing happen with Neptune's rotation?
2
votes
0answers
25 views

Is all of the data from the same program that found the Wow!-signal analyzed?

I just read on Wikipedia that... By 1977, Ehman was working at the SETI project as a volunteer; his job involved analyzing by hand large amounts of data processed by an IBM 1130 computer and ...
2
votes
2answers
59 views

Is Earth's true anomaly roughly 1 degree currently?

I wrote software which uses GMT real time to calculate Earth's mean, eccentric, and true anomaly. I encountered a bug where after reaching 360 degrees, instead of flipping back to zero, it subtracts ...
2
votes
3answers
149 views

What process shaped Ultima Thule?

When I see this picture, I'm trying to understand how these two elements merged together and have two hypothesis : two balls of lava in fusion together two solid rocks fused at their contact point ...
3
votes
1answer
47 views

Would one have to be more than halfway to the Oort Cloud for the Sun to appear as bright as the full moon?

Is this correct? If the Sun is 400,000 times brighter than the full moon am I correct in figuring that one would have to be about 632AU from the Sun for it to appear as bright as the full moon. If ...
1
vote
0answers
44 views

Can you go blind if you look at the sunrise and sunset? [duplicate]

Everyine knows its dangerous to look directly at the sun, but can you look safely at sunrises and sunsets without going blind? Because the uv radiaton and the light is much weaker. Or is it still very ...
6
votes
1answer
109 views

Will there be public access to the New Horizons data from Ultima Thule?

I imagine New Horizons data from its encounter with Ultima Thule (2014 MU69) has started arriving. Does anyone know if this data is public? And, if so, how you can access it?
0
votes
1answer
72 views

Time-frame regarding cosmic expansion and the bound state of the Virgo Cluster

Due to accelerating cosmic inflation, other galaxies and galaxy clusters will eventually race toward the Hubble horizon apparently away from us, placing them effectively out of our sphere of influence....
2
votes
2answers
43 views

What are the aberrations of an SCT? And how can they be eliminated?

The Schmidt-Cassegrain telescope is amazing! It is compact, suitable for astrophotography ,and it requires little to no collimation. However, the SCT has some inherent optical issues. What are they? ...
9
votes
2answers
2k views

What is the bright object above the moon in Sudbury, Ontario?

There is a bright object above the moon in Sudbury, highly visible to the eye, nothing else as bright in the sky except for the moon. I'm looking around 6 and 7am. What is it ?
1
vote
0answers
44 views

Why is the moon more visible during the winter? [closed]

I was curious to find out that as to why, the moon looks more sharper during the day in winter, whereas it's almost not visible during summer.
1
vote
3answers
68 views

Seeking advice regarding buying a telescope

I'd like to buy a telescope with a focal length of 700mm and an aperture of 60mm. Would I be able to use a telescope of this power to study the closer planets (for example Mars and Venus) and ...
48
votes
4answers
10k views

Why does it take so long to transmit an image from New Horizons to Earth?

I just got the news that the New Horizons space probe has passed by some remote planet on the edge of the solar system. I was surprised that the guy from NASA says that it might take 24 months from ...
0
votes
1answer
60 views

Is it possible for particles to be accelerated FTL inside BH travelling towards the singularity? [closed]

Maybe just maybe it is possible for a particle to travel FLT inside of black hole because of the singularity gravitational force This could be due to the fabric of space it self falling towards the ...
2
votes
1answer
39 views

Is the Bondi Radius the Same as the Schwarzschild radius?

$$2MG/c^2$$ This is the expression for both, but some authors use one name and it has confused me. Is there any distinction?
7
votes
1answer
414 views

Is the moon's orbit circularizing? Why does tidal heating circularize orbits?

The moon has an elliptical orbit (of course), but as it inches away from the Earth each year, does its orbit become more circular and how come? Io's orbit is becoming more circular due to tidal ...
2
votes
2answers
55 views

How far above the Earth's surface does interplanetary space begin?

The Kármán line is often cited as the beginning of outer space. The Voyager probes have identified the boundary between the heliosphere and interstellar space. Is there a agreed upon definition of ...
1
vote
0answers
30 views

How to convert a function of keplerian elements to a function of equinoctial elements?

I need to convert the Keplerian orbital elements to the equinoctial elements and then use the converted elements"equinoctial" in the function "d" below. To do this, first, I converted the Keplerian ...
1
vote
2answers
85 views

Questions related to the reflection of the moon

What would happen if we painted the whole moon with black, will it still reflect light, or it will become invisible? What would happen if we painted the whole moon with silver paint or make its ...
0
votes
1answer
80 views

Why are blue stars the hottest? [duplicate]

I know that blue stars are the hottest and youngest (according to Universe Today). But what makes them blue, instead of other colors like purple?
2
votes
1answer
79 views

Why the Sun-Jupiter barycentre is outside Sun?

The Earth-Moon barycentre is said to be inside Earth. But Moon-Earth mass ratio (1.2%) is larger than Jupiter-Sun mass ratio (0.09%). Then how come the Jupiter-Sun barycentre is outside the surface of ...
6
votes
1answer
127 views

How did they make a video of the center of the galaxy, and what is it exaclty that's flashing there?

The ESA video ESOcast 173: First Successful Test of Einstein’s General Relativity Near Supermassive Black Hole includes a clip of images of stars at the center of our galaxy orbiting around SgrA*, a ...
1
vote
1answer
42 views

Why aren't corrector plates aligned with the center of curvature in an SCT?

According to wikipedia, Schmidt corrector plates must be aligned with the center of curvature to eliminate the spherical aberration. However, in compact SCT designs by Celestron and Meade, that is ...
3
votes
3answers
69 views

Why is it impossible to estimate the inclination of an exoplanet with the Radial Velocity Method?

The formula of the radial velocity is: $$v_i= V - K(\sin(f_i+\omega)\ + e\sin\omega),$$ with $$K = \frac{m_p}{m_s+m_p}\frac{na\sin i}{\sqrt{1-e^2}}.$$ Being $V$the systematic velocity of the system, ...
4
votes
0answers
32 views

Strength of core-envelope coupling in stars

For a star with a given Zero-Age Main Sequence (ZAMS) mass, as a function of metallicity how strongly is the star's core coupled to its envelope? I understand that the core-envelope boundary is only (...

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