# All Questions

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16 views

### Big what, how can we tell?

Why was the particle smaller than a grain of sand at the Big Bang and not something very massive that left all this dust and stuff out there.
30 views

### How can a mirror see what the eye can’t

How does a mirror pick up light from vast distances away and if that light can reach a mirror why can’t we see that light.
16 views

### Does this CHEOPS first light image imply bad astronomy?

@KeithMcClary's comment under lousy mirror corrected by software links to Bad Astronomy's First Light for the Exoplanet Hunter Mission CHEOPS Goes Tetrahedral which shows the image below. I ...
22 views

### Why do radio telescopes, but not shorter wavelengths, have this Big Data problem?

Only with new radio telescope arrays like ALMA and SKA, have I heard of this "problem" with too much data come up. Too big to store. That one cannot archive it all for future studies, but that one has ...
29 views

### Satellites traveling in single file across the sky [duplicate]

I just watched 46 (best count) satellites traveling in single file, about 3 second intervals between them. Is that possible? I don't want to believe they were UFO's. Time was ...
74 views

### The Solar System formation

I've recently watched one conversation (I won't post a link since the conversation is not in english) involving a physicist (at least he claims so), who spoke about probabilistic estimates of the ...
41 views

### How variable does a star have to be, to be a variable star?

Variable stars are stars whose apparent magnitude varies. But there are so many phenomena that can cause a star to be variable, that I would expect all stars to be variable. A rotating star has a ...
78 views

### Largest body in the solar system that a baseball thrown by a professional pitcher could escape

What is the largest (most massive) known body in the solar system that a professional pitcher could throw a baseball off of, i.e. that has an escape velocity lower than ~102 MPH? (45.33 m/s)
47 views

### lousy mirror corrected by software

Would it be possible to get a terribly shaped mirror, like a large sheet of something reflective, give it a general shape like a telescope mirror, but not anywhere near as precisely shaped as in a ...
27 views

### Henyey method for interior parts of the star

Does there exist a code that implements Henyey method for interior parts of the star?
29 views

### Where can I find data for fast radio bursts like FRB 180916?

Where can I find Strength over Time for FRB 180916? Or at least day+time of remarkable events. Is there some good data for other FRB that hit the earth for the last 2 years?
1k views

### Are we seeing a conjunction these mornings?

I have a doubt about planetary conjunction. These days, we can see Saturn, Mars, Jupiter and the Moon close to each other. I mean if Saturn, Mars, Jupiter and the Moon were in conjunction with each ...
147 views

### Is there a distinction between NEOs and near-Earth asteroids? Is there a difference?

My "real question" is in Space Exploration Meta (neo (near-earth-object) and near-earth-asteroid tags, do we need both?), but I think that astronomers will be able to help understand the situation and ...
37 views

### When Betelgeuse goes supernova, will the explosion hit any neighboring stars?

There is evidence Betelgeuse might go supernova "soon". Are there any stars in the vicinity of Betelgeuse that are close enough that they will be hit by the explosion of this supernova? What would be ...
22 views

### What are good resources to study Gravitational Waves?

I am undergraduate student having basic knowledge of Physics. I'm looking for resources (books, video lectures, research papers, etc) to study Gravitational Waves from scratch, I think initially I ...
52 views

### Would the Event Horizon Telescope be able to produce a superior image of Betelgeuse?

Current images of Betelgeuse are already amazing, but I was wondering if the EHT could be able to make a significantly better image, given that Betelgeuse is pretty big and pretty bright?
72 views

### Was the Earth-Sun distance ever calculated based on the time difference between night and day?

If we define sunrise and sunset as the time when the center of the Sun goes over the horizon then day time is a little bit shorter than night time because from a single point one cannot see a complete ...
36 views

### Field rotation and observing the moon

For stars, field rotation can be accounted for with an equatorial mount aligned with the Earth's axis and turning at the correct rate. Since the Moon's orbit is on a different axis then the Earth's ...
45 views

### How scientists estimated the number of near-Earth supernovae over the last 11 million years?

According to this article on wikipedia, An estimated 20 supernova explosions have happened within 300 pc of the Earth over ...
26 views

### How to understand the meaning of this International Occultation Timing Association (IOTA) lunar occultation of Mars map?

Earthsky.org's Watch Mars disappear behind the moon on February 18 as well as Moon occults Mars morning of February 18 include the image below and credit it to The International Occultation Timing ...
90 views

### Why does the Sun track out a seemingly sinusoidal path on the celestial sphere?

The question arose because I wanted to understand the path of the ecliptic after reading about it here: https://community.dur.ac.uk/john.lucey/users/solar_year.html Is the sinusoidal path due to ...
53 views

### How many members of the IAU typically attend votes?

One of the talking points of people how think that the definition of a planet should include Pluto is that during the 2006 vote on the definition of a planet, only a small percentage of the members of ...
2k views

### Daily magnitude of Betelgeuse

I tried searching on the internet and could not find anything, so does anyone know if there's a website which tracks and shows Betelgeuse's magnitude daily? I just went out today and saw that it's ...
55 views

### I saw this ball of light moving across the sky [duplicate]

As I stated in the title, I saw this ball of light moving across the sky. It wasn't moving fast, but it wasn't moving slow. So, I was sitting my dad's car when I looked through the windshield and at ...
28 views

I search for lightcurve Kepler data: time $t_i$, flux $F_i$ and measurement uncertainties $\sigma_i$ I need processed data (after removing trends, normalized, etc.). Where can I find it?
76 views

### Do pulsar beams interact with the interstellar medium?

Pulsars are rotating objects that emit a beam in a direction that is not aligned with the axis of rotation. Because of this, we see them as a periodic pulse. If the beam isn't towards us, we don't see ...
202 views

### Betelgeuse in false colors, is this common?

First, take the original Betelgeuse image from ALMA and remove red and green channels. Then boost the blue channel luminosity by x10 to x20 and a lot of detail pops out. This is the resulting image ...
68 views

### On the anniversary of Pluto's discovery: the statement that Pluto is a planet [closed]

February 18 marks the 90th anniversary of the discovery of Pluto, the ninth planet from the Sun. For 76 years Pluto counted as the undisputed ninth planet until the International Astronomical Union ...
47 views

### Star and Galaxy Visualization [closed]

Is it possible to visualize star and galaxy at the same time in our minds? Suppose you think of a star, you made a picture of it and then you create a picture of a galaxy in your mind. You must have ...
83 views

### Are Sun-Earth L1 & L2 points generally considered outside the Earth's Hill Sphere?

This image from Wikipedia of the SE Lagrange points and the Hill Spheres suggests that the SEL points are outside the Earth's Hill Sphere. (The Hill spheres are the circular regions surrounding the ...
122 views

### How long could an ocean last in space?

If all of Earth's oceans were suddenly moved into outer space, how long would it take for them to evaporate? My understanding is that water evaporates straight away in space... but what about when it'...
53 views

### Gas Planets composition and gravitational effects

It has been postulated that Gas Giants have a solid core and an obvious gaseous atmosphere. Question: As the gas is a state of matter and gravity draws all matter inward, is the reason the gas is ...
81 views

### In Orion, how close in local distance are the closest of the member stars?

All the members of Orion are within the Milky way, and some of them look pretty close to a neighbor. And could the bow be an effect similar to the Radcliffe Wave?
57 views

### Color index B-V of the dimming Betelgeuse

Using AAVSO light curve generator I have plotted V and B magnitudes of Betelgeuse in the past 150 days to see trend of B-V color index. If dust would be the cause of the recent drop in the star ...
59 views

### How strong are the strongest Ioquakes?

Jupiter's moon Io is the most geologically active celestial body in our system. It has the strongest volcanoes and quakes. Of course in practice these quakes wouldn't be as dangerous as on Earth for ...
66 views

### Are there any IAU members on the astronomy stack exchange? [migrated]

Are there any members of the International Astronomical Union that are active on this astronomy stack exchange?
25 views

### What was the field of view of the Ohio State University Radio Observatory of Wow! signal fame?

This answer to Did comets 266P/Christensen or P/2008 Y2 (Gibbs) cause the Wow! signal? points out that the comets in question were nowhere near where the radio telescope was pointed. Wikipedia says ...
37 views

### Did comets 266P/Christensen or P/2008 Y2 (Gibbs) cause the Wow! signal?

Continuing my fascination with the Wow! signal, I stumbled upon an article from 2016 titled Famous Wow! signal might have been from comets, not aliens. It describes the hypothesis that the signal ...
42 views

### What coordinate system is at rest relative to the center of the galaxy?

I am given equatorial coordinates and I need to transform them into a coordinate system that is at rest relative to the center of the galaxy. The closest thing I could find is galactic coordinates ...
70 views

### Are there celestial bodies that are about as far away as the Sun?

Just curious. The Sun is 500 light seconds away from the Earth depending on time of the year. The orbit of Mars is about 50% as far as the Sun, the orbit of Vesta about 150%. Is there / Are there ...
51 views

### Gaia/Hipparcos overlap

Is there any kind of concordance available between the sources in the Hipparcos catalog and the Gaia DR2 catalog? I.e., mapping the Gaia DR2 source_id to the Hipparcos HIP number?
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### Is it plausible to use other stars for the proposed FOCAL mission instead of the Sun?

For some time, the far-reaching and speculative idea of using the Sun as a gravitational lens has been floating around. See this and this. This would require sending a spacecraft about ~550 AU of a ...
29 views

### What are the various imperfections involved in synthesis radio telescope? [closed]

Explain in terms of surface accuracy, receiver noise, polarization purity, gain stability, geometric model errors, Atmospheric conditions, Radio Frequency Interference, etc. How these variables ...
93 views

### Create an inhabited black hole

Hello I was watching one of Isaac Arthur's videos about the end of time and i just got a crazy idea Is it theoretically possible to "create" a "solar system" that would look like a supermasive black ...
71 views

### Is the Big Bounce Theory valid? If so does that mean all this have happened before?

IF the universe is just an infinite loop of events from expanding to contracting does that mean all this has happened before? The initial conditions for the next big bang would (or rather could) be ...
43 views

### Effect of shock waves on the chemical evolution

How do the shock waves affect the chemical evolution of interstellar medium or circumstellar medium of evolved stars etc?
81 views

### How fast does a spacecraft have to be to enter a primordial black hole without being torn apart?

If there really is a primordial black hole beyond the Kuiper belt, we can send a probe to the black hole and into it. But how fast must the probe be in order to enter the black hole without being ...
73 views

### Can the WISE telescope detect black holes?

Black holes are hot, aren't they? With its infrared scan, could the WISE telescope also detect a black hole? The hypothetical planet beyond the Kuiper belt could actually be a primordial black hole. ...