# Tag Info

22

If you set the date to 2018-04-06, Stellarium shows the Moon and planets in positions matching the example image. Any good planetarium software should produce a similar result. Most likely the vendor cut and pasted two screenshots (note the seam) for April 2018, overlaid "January 1973," and hoped customers would not check. Perhaps you could ask them to send ...

8

Scientifically there's little to gain when you look through a telescope with your own eyes. Attach a camera to the telescope and you immediately document what you observe and take out the subjective factor from it at the same time and allow careful analysis and more detailed. Additionally you gain improved sensitivity enhanced observation duration and ...

7

Python is gaining popularity and replacing MATLAB in many fields of science as the tool for fast prototyping and writing research code. Have a look at http://www.astropy.org/ http://www.astropython.org/ https://python4astronomers.github.io/ http://www.astroml.org/ http://asteca.github.io/ for example. (I'm not working in astronomy as a researcher but in ...

7

Have you tried nova.astrometry.net? They set up a web service for doing more or less what you're talking about.

7

Finding an astrometric solution from an image with Astrometry.net is usually called plate solving. As mentioned in the comments, it is based on pattern matching, using a large set of databases that are pre-computed for various field of view and plate (or pixel) scale. The ArXiv paper Astrometry.net: Blind astrometric calibration of arbitrary astronomical ...

6

I would recommend MPA Garching's Gadget code for cosmological simulations of structure formation. It's primarily gravitational, but I do believe you can include gas effects as well: GADGET computes gravitational forces with a hierarchical tree algorithm (optionally in combination with a particle-mesh scheme for long-range gravitational forces) and ...

6

Short answer: no. Why not? because the mirror is placed at a position in the optical train such that it controls the wavefront phase and tilt of each subsection, "subaperture" of the incoming beam. Once an optical system has formed an image, all phase information is lost. There are some software methods which can correct for simple aberrations such as ...

5

For computer software, the easiest way to take a sphere (and/or hemisphere) and flatten it into a flat shape (usually a rectangle) is the equi-rectangular projection (also known as the plate carrée), because it has the simplest formula relating pixels and coordinates: $$x = w \times \frac\lambda{360} + \frac w2$$ $$y = -h \times \frac\phi{180} + \frac h2$$ ...

5

Stellarium is known to be accurate. Star and planet positions in 1973 are very well known, and correctly shown in Stellarium. At that time and place, Cetus and Taurus are rising in the East and North East, where Saturn is just about to rise. Lynx is on the horizon in the North. The Horizon. Bootes is about to set in the West. The sun in low on the horizon ...

5

360° panoramic media conventionally use equirectangular projection and a 2:1 aspect ratio. I made a still panorama this way: Configuration > Tools > Screenshots: Custom size 2048 x 1024 View > Sky > Projection: Cylinder (i.e. equirectangular) View > Sky > Stars: Relative scale 0.70 (limits brightest stars to a reasonable size) FOV 180° (Ctrl+Alt+1) ...

4

Ok go on Stellarium then hover over the left side of the screen afterwards click on the location and select London, England (City Of London is the original walled city), then go and hover over the left side of the screen and select sky and viewing options and in the sky section and select the air pollution level from location database then it will ...

4

As an observational astronomer, most of your programming will be to perform data analysis, data exploration, and possibly image manipulation. Previously much of this was done with IDL, and the analysis pipelines for several/many/all(?) telescopes still rely on IDL. As GreenMatt points out though, IDL is on its way out. Since you have to buy a license to ...

4

A profession in astronomy can entail various things. Unlike what other people are saying, you don't have to have a PhD in astronomy to do work in this field, to be an astronomer. There are other options, but you will have to work hard. Study as much physics and mathematics as possible. Astronomy is essentially a branch of physics. If you're still in ...

4

Every pixel value $S_i$ on the detector at $\vec x_i$ has some error $N_i$: CCDs for example have a background noise $N_\text{bkg}$ from read-out electronics, thermal noise, and sky background, plus a Poissonian photon noise $N_S=\sqrt{S}$. In many cases this noise follows a Gaussian distribution reasonably well. After subtracting the background, a ...

4

As I do not want to reinvent the wheel, is there any star recognition framework that you've heard of? Preferably open source, the language is of marginal importance as long as I can get the relevant data in and out. I'm thinking of something that I can feed with an image file and get back an array with the recognized objects with their x/y ...

3

I've had success with Hugin. It's a panorama creator, but it can be used to rotate, resize, and relocate images into a coherent whole. It has a few different automated profiles, but sometimes they are a bit off with star stacks. You can manually select the guide stars though. A really good program for after that is GIMP and the plugin G'MIC to stack and ...

3

I'm going to describe the steps that I followed to show 2004 BL86 in Stellarium in my notebook: Open the Configuration Window by pressing F2 Select the Plugins tab and from the left list select Solar System Editor Click in the configure button at the bottom Go to Solar System tab in the opened window Click the button Import orbital elements in MPC format... ...

3

Horizons Ephemeris generator can give you a planet's position and velocity vectors at a specified time. This is one set of possible options: Clicking Generate Ephemeris on that page will give you position and velocity vectors: Above the position and velocity vectors are the Julian date as well as the more conventional date. Wikipedia can give the masses ...

3

The most commonly used packages for generating graphics in astronomy are probably IDL -- this has long been the most popular, in part because there is a lot of astronomical data reduction and analysis code written in IDL. SuperMongo The Python package matplotlib The apparently uniform style you refer to is probably a historical combination of IDL and ...

3

You should go to the site https://fits.gsfc.nasa.gov/ where you can read about the FITS data format. This site also has utilities for examining and viewing the data. Most of your concerns about this data should be answered by the documentation on this web site.

3

The header of a FITS file is ASCII, and points you to further information. Calling head -n 1 example.fits directs you to "'Astronomy and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H". A software to view FITS images is ds9 (yes, that makes it hard to google...). Alternatively, there's skycat. Both can be used to view and do basic ...

3

You might take a look at this 2006 paper by Thomas et al. on centroiding algorithms for astronomical adaptive-optics (AO) systems, which includes a detailed discussion of error estimates for the centroid position using different algorithms. The approach you describe in your answer corresponds to what they call "simple centroid" (Section 3); they refer to a ...

3

The documentation is somewhat confusingly written. It refers to a \$PSRSOFT_DIR as a shortcut to where you unpacked the tarball, which everything is done relative to but doesn't require this shell variable to be set. So there is 1 thing to do and then you can do 1 of 2 things. The mandatory thing (as it says in the docs) is to copy the psrsoft/config/profile....

2

Aladin is a good way to do visualization from multiple catalogs. MAST also offers a cross-mission search.

2

Perhaps you are looking for the backup function File -> Backup... and to restore the settings File->Restore...

2

I was able to get the Cartesian orbital vectors for all the major bodies from HORIZON at the J2000 epoch only. I could extend the coverage forward thru time. It’s easy to get data overload doing this. My simulation is modeled using the Laws of Gravitation and Motion alone. This gives results that are surprisingly close to those published. Running the ...

2

MESA It is designed specifically for stellar evolution. There are many modules that you can play around with, including binary interaction.

2

This is really a computing problem, but I suppose the only point from an astronomical perspective is what the RA, Dec distributions of your catalogues look like. I'm not that familiar with optimal search techniques but I guess that you want roughly similar numbers of stars in each region. If your catalogue is just of the brightest stars, then these are ...

2

There are two things I can see in this code: First, the Julian date is measured from Midday, whereas the unix epoch is measured from midnight. jdn = 2440587.5 + when / (1000.0 * 3600 * 24) should be the correct expression. Secondly, alpha = atan(cos(epsilon * degtorad) * tan(lambda_ * degtorad)) calculates a right ascension in radians, you should convert ...

2

This frustrated me as well when I first used the Tycho-2 catalog. Not finding a well known bright star can be disconcerting. Quoting from http://heasarc.nasa.gov/W3Browse/all/tycho2.html Supplement-1 (not part of this HEASARC database but available at ftp://cdsarc.u-strasbg.fr/cats/I/259/suppl_1.dat.gz) lists stars from the Hipparcos and Tycho-1 ...

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