Astronomy Definition and 833 Threads

Hi! So it's been a while since I've done this and uh I also haven't slept well over the past few days so literally nothing is clicking. I have so many questions about this celestial sphere business. Please bear with me. It also doesn't help that our notes have like 5 different diagrams of the...

I am currently applying to Astronomy, Astrophysics, and Physics Ph.D. programs. I am doing a Ph.D. because I can't wait to learn more about cosmology and to computationally model galaxies, but I understand that jobs as professors are rare. Looking at backup plans, I've heard that some academic...

Alright so I'm a freshman in college studying physics with astronomy specialization. I want to eventually get a PhD and work for a space agency or maybe even become an astronaut. I've been told that having experience in the Air force looks much better when applying to work for a space agency...

From deep galaxy counts, it is estimated that there are about 40 billion galaxies in the observable universe (not including probable multitudes of dwarf galaxies too faint to observe). Assuming that the mean age of these galaxies is 10 Gyr, and that each one goes through an AGN episode once...

Homework Statement I have the following variables: f = .93 m f(e) (eyepiece) = .0082 m distance toJupiter pj = 588 E^9 diameter of Jupiter dj = 139822 E^3 Find the height of the image of Jupiter created by the objective lens of a telescope. Homework Equations M = -q/p q = f Where M is the...

https://www2.jpl.nasa.gov/teachers/attachments/parallax.html It's written that they find the distance by calculating from the parallax angle. But how do astronomers find the parallax angle?

Hello. I am currently trying to calculate the equation of a hyperbola, which I have little experience with. The hyperbola has a "sphere radius" of 153mm and a "hyperbolic factor" of 21500. I haven't been able to find anything online about what these mean and am lost. The parameters where given...

Especially today’s younger generation...

Modern astronomers use parallax to determine the distance to a star. Parallax is based on the stars of the stellar universe that are stationary where the change in the angular position of a stationary star is measured after the observed on the Earth propagates the distance of the Earth's orbital...

Hi there, The book “Foundations of Astrophysics” by Ryden and Peterson states that one measures azimuth in the horizontal coordinate system eastwards starting on the northernmost point of the horizon circle. Thus, east becomes 90 degrees, et cetera. Wikipedia and other sites back this up...

Hi there, I love physics and I'd like to begin a bit of astronomy. I want to invest in a beginners telescope but I haven't a clue about what to buy. Some that I'm looking at are linked here: https://www.amazon.com/dp/B00XQMLA7Q/?tag=pfamazon01-20...

Hi fellow thinkers, my main area of interest is in QM. However I am always interested in new discoveries and experimental proofs of outstanding theories. Looking forward to joining the discussion with others who, like me, enjoy absorbing new information... S.P.W...

Hello PF community! Quick introduction: I'm a fresh-out-university mechanical engineer working on a telescope altitude-azimuth mount hobby project. The mount will be designed using rotary platforms (powered by internal motors) to move the mount structure in the altitude and azimuth directions...

Hi everyone, My name is Zack and I'm new to the forum. I recently changed careers from audio engineering to astronomy and am queuing up to attend the University of Oregon in about a year. I'm a big fan of all the historic great astronomers, scientists and others who have contributed to the...

I am currently an undergraduate researching Supernovae. We are doing some luminosity calculations using CIAO and HEASOFT which take anywhere between 7 to 13 hours for each remnant. To make the process quicker, I wrote a script that reduces that time to about 40 minutes for each remnant. One of...

Hello there, I am currently a senior undergraduate Astronomy and Astrophysics major at Villanova University. With the GRE and graduate school applications coming up I have been wondering if it would be beneficial for me to either take a gap year or to possibly take a 5th year of undergraduate...

Could anyone please guide me how to do these problems?

Homework Statement The orbits of the planets remains extremely stable over long times however this not always true for comets. Can you explain why not? What hazards might they encounter during their travels? Homework Equations None The Attempt at a Solution I think that due to the comet's not...

1. The problem statement, all variables, and given/known data Satellites orbiting the Earth are often put into orbit at different heights around the planet. What affect will this have on the motion of the satellite and how exactly would the motion of a very high orbit satellite differ from one...

1. The problem statement, all variables, and given/known data Venus is sometimes described as either the “Morning Star” or the “Evening Star”, since it can only be seen near sunrise and sunset, very close to the Sun in the sky. Why does Venus always appear close to the Sun in the sky for an...

Could this be a possibility at some point? Since entanglement is not affected by distance, could we send cameras out to extremely distant places and get instantaneous signals? Only the image sensor would have to be entangled. It would still take the same amount of time as usual to get the camera...

I've been trying to understand how we know that the observable universe is flat, and I'm having difficulty finding any sources that explain exactly how the calculations were done. On this WMAP website (https://map.gsfc.nasa.gov/mission/sgoals_parameters_geom.html), it says: "A central feature of...

Hi, Some time ago I was looking for lightning ball videos on youtube. I observed some strange phenomenon recorded on one of the videos. Before a lightning ball is created, some "dark" ball is coming from above and then it immediately changes to the lightning ball which is moving at different...

Greetings, I wonder if someone could please kindly give a physics explanation for the phenomenon of circular star trails when Earth is moving 67 times faster laterally than it is rotating? Thanks very much in advance...

Why do galaxy and galaxy clusters look so colorful?

Hi guys! I'm a high school student and I love Physics. I hope this site will help me learn and understand a lot of (new) things! :)

Hello. I couldn't sum my entire question in the title, so here it goes: I have a friend that needs information about the content of Iodine and Molybdenum in stars (from as much stars as he can). There are references to the content of many stars in books and papers, but most of them don't give...

I am doing research for my aerospace engineering dissertation to plan a mission to a Jupiter trojan asteroid. I was researching the type of outgoing trajectories used in missions such as JUNO, Galileo and Europa and noticed they all use Earth as a gravity assist in getting to deep space. Surely...

Can anyone tell me if its possible to do a BSc in physics and astronomy after doing bachelor's in computer science? I was looking at applying for a Masters in physics and astronomy but looks like BSc is kind of a must because of the lack of training in physics I have. I looked at schools like...

I read in a popular science magazine in the UK that "recent" observations of the universe indicate that the number of galaxies in the the universe is actually so vast that Olbers paradox is still a paradox. The short article postulated that they had solved the paradox by proving that light from...

Astronomer Pamela Gay discusses the some of the false information we might encounter in popular astronomy information. Presented as part of the Balticon 2012...

Hi guys, I need help, more specifically in a technical issue. I started my thesis with an Astrophysics professor and he gave me a topic of "M dwarf spectra with cyclotron bumps from SDSS". In short, I am given spectra of a number of cylotron bump M-dwarfs (CBMDs) from unusual quasar search from...

I got a guaranteed slot in a university that offers a physics program but I'm doubtful if that is the right choice. I could take this physics program or I could maybe move to another city and study astronomy there. I'm interested in particle physics, mechanics, astrophysics and...

As the title says...I am hoping for recommendations for the 2017 summer. Specifically, Southeast US, one week residential, hopefully under or around 500 dollar physics or astronomy camp for rising 9-12 graders. Thank you very much.

1. Question Suppose you examined the spectrum of some nebulosity surrounding a main-sequence spectral-type O star and found that it contained no emission lines, only the continuous spectrum of the star. What conclusions could you draw about the nature of the interstellar material around that...

Lets suppose that two points A and B are very close together compared to their distance from an observer who is very far. Suppose the distance from observer to point A is DA and to point B is DB. How precisely we can find the distances separately.

I am 16, and I LOVE SCIENCE. I don't really know why, but I do know that I want to be some sort of scientist. I am thinking about doing astronomy or maybe quantum mechanics. I think the two is a fascinating occupation. I also hope to find other science careers that might be interesting. I am...

I'm in the 11th hour of studying, and have run into a problem I can't seem to tackle from an old exam. I may be making some foolish mistakes, as I've now been staring at this thing for entirely too long. 1. Homework Statement (a) Calculate the force due to radiation pressure experienced by an...

Hey!So, I applied to some universities for Physics and astronomy before I ended up with my grade 12, first-semester mid-term mark of a 74 in physics. I had an 87 last year with the same teacher. I've been accepted everywhere I applied, which is great, but I'm scared that, because I'm not doing...

I want to describe a planet that has 13 fifty-two day months and a 36 hour day. IF someone could point me to a place where I can figure this, it would be appreciated. What's the math?

Homework Statement At first I needed to calculate the angular resolution of a telescope (diameter 1m, for visible light) so I used θ=1.22λ/D and got 4.88x10^-7 rad. Now I am asked: "If we wished to use this telescope to image the moon, what is the closest distance two objects can be to be...

Hi all, I am going to apply for graduate school next fall but I am not sure what computer language is most frequently used in astronomy/cosmology graduate programs. Any ideas? Also, in the mean-time I want to work and earn some money before I apply next year. What jobs...

A popular video I just watched described Fred Hoyle's discovery that the elements of the universe are created in stars. Key to his theorizing was the prediction that fusion would produce of a new state of carbon that had never been observed and which theory predicted would be unstable. Hoyle...

I am a senior in high school, I am applying for universities right now. I have wanted to pursue astronomy for several years now, but I am wondering if I should major in astronomy or physics as an undergraduate. I've read online that physics major as undergraduate is an option to pursue a ph.D in...

Some observed neutron stars rotate hundreds of times per second. Speeds at the surface of these stars are as much as 15% the speed of light. These huge speeds are generated because angular momentum is conserved when a large rotating pre-super nova star collapses into a neutron star. The...

Hello, I am currently considering on buying a telescope to do some of my own research and for sight seeing. Any recommendations? I would prefer to have a telescope that requires me to use code or at least a computer so I can familiarize myself with the mechanics.

1. The problem statement, all variables and given/known Homework Equations show that a hydrogen gas cloud at 10000K is about twice as optically thick at the Balmer limit compared with the Paschen limit. Assume that the H atoms are in Local Thermodynamic Equilibrium, the Gaunt factor is unity...

Hello! I am a bit confused about Kepler 3rd law for circular orbits. So assume you have 2 bodies of masses M>m orbiting in circles around their center of mass. As the center of mass passes through the line connecting them, they must have the same period. But according to Kepler's 3rd law, this...

Hello everybody, according to your experience please give me an advice, Can i go to an astrophysics& astronomy master's degree with a bachelor's degree in law ? I've studied Physics and Math 2 ( calculus, mechanices,algebra) in high school. i was getting high marks at them and I am so...

Hello everyone, My name is Abishek and I'm a mechanical engineer from India. Astrophysics is my passion and everything I think about.But due to my background I thought It would be better to do a MS in Astrophysics after doing my Engineering,cause If I fail I could rely on my engineering...