Useful astronomy links

Latest additions: January 14, 2010. New and recent items marked with

Sometimes, it seems that finding astronomical data, software, and utilities online is like drinking from a fire hose -- there's just so much out there, much of it free. I've made an effort to put together a list of links, downloadable software, and online utilities that I've found useful. Mostly so I'll know where they are and don't have to search for them elsewhere.

I've also added lists of sources and vendors.

Observing

Clear Dark Sky Clock -- find out what the weather for your observing site will be like. Most important, it provides a prediction of seeing -- how badly the atmosphere is blurring star images.

• My local Clear Dark Sky clock

NASA weather satellite images

Jet Stream map from Weather Underground -- generally, high speeds = bad seeing.

General telescope utilities

Ron Wodaski's free CCDCalc utility for determining fields of view of any telescope/camera combination. Also displays framing of specific deep-sky objects.

Aberrator -- a program that simulates star test images. Free. From Cor Berrevoets in Belgium.

Metaguide -- cleans up distorted Airy disks in real time, even when seeing is bad, to enable collimation with a webcam. Free.

Roddier -- a program to help evaluate quality of optics using a very sophisticaed star test, inside and outside focus. Example of what it does.

download the program

Explanation (in French)

Yahoo newsgroup (in English; you'll have to join to use the group)

Cookbook on how to run the French software ("I don't know what I'm doing but I know what buttons to push")

PHD guiding -- free autoguiding software from Stark Labs

GuideDog software -- autoguiding software for webcams. Free.

Guidemaster -- another autoguiding package for webcams. Free.

MyScope -- by Andrew Johansen. PEC (Periodic Error Correction) table editor, utility, and general scope control (includes handset emulator). 

Televue TVFocus software. With this free software, the correct electronic digital indicator (Swiss quality and very much not free), the correct interface cable (seems very expensive but it has an optocoupler, not just dumb copper wires), and an available serial port on your computer, you can have a remote focus position readout. You may have to cobble together some hardware to adapt it to your telescope.

WCS Scheinern -- a program by Wolfgang Ruthner in Austria. This program semi-automates the process of polar drift alignment; you tell it your scope focal length and camera, it looks at star image drift in specific parts of the sky and puts a "target" on the monitor screen. You crank the equatorial wedge adjustment screws to bring the star to the target, and check again for drift. There are actually several versions, one for webcams, one for Meade DSIs, one for ImagingSource cameras.

Bahtinov Mask Generator. Generate a template for making a Bahtinov mask, allegedly a better alternative to a Harmann mask.

• What is it? Here's a Cloudy Nights thread (must be logged on to see images)
• Another thread
• And another
• Commercially made Bahtinov masks:
• Somebody is making these commercially but they're expensive. I'd make a paper one to try, first.
• A cheaper alternative
• And another
• Here's a video of what one sees as you go through focus.

It turns out that there's something similar to a Bahtinov mask, that works slightly differently. Called a Carey mask. Looks interesting, but I can't find any commercial sources. More info:

• The inventor's announcement, with templates. Note that his slots have rounded ends -- something I thought the Bahtinov masks should have had too. 
• Discussion on "Ice in Space" forum, with inventor
• Cloudy Nights forum discussion
• An animation of a Carey mask in action. Another. And finally this one.

And if that isn't enough mask varieties, there's yet another, that perhaps should be called a Lord mask (info here or here). Works like a Bahtinov mask, but less fiddly to make.

Telescope certification by Wolfgang Röhr, Germany.

• Ever wonder how good your scope really is? Well, the manufacturers never tell you. It would be nice to find such a service in the USA. He uses a Zygo interferometer.

Meade telescope utilities

Download site for Meade Autostar Suite updates

Download site for Meade Envisage (DSI camera control software) updates

Meade Autostar Update client application (software used to load new firmware into Meade Autostar telescopes)

Alternative to, some say better than, Meade ASU: Starpatch

Download latest Meade Autostar II telescope firmware

Dick Seymour's Autostar patches (add / modify certain useful features)  See also here.

Andrew Johansen's "Myscope" telescope PEC (periodic error) and scope settings editor utility. VERY useful and free!

Meade telescope tech info

Got problems with your Meade scope and Meade's customer service isn't helping? Won't sell you parts? Slow service / no service / bad service? Rebate check missing? Here's who to contact in government to file a complaint and get action (not just for Californians, either).

Do you get lost in the Meade Autostar II menu? Go here and copy the image file of the entire menu tree. You can resize this as needed, print it out, and laminate it or put it in a sheet protector to use at the telescope.

Lots of tech info at MAPUG -- the old Meade Advanced Products User Group, started with the LX200 Classic. Some GPS info.

The Files section at the Yahoo LX200GPS newsgroup has lots of schematics etc.

MeadeLX200GPScom (that's not its real URL) has tons of tech info. Also "back issues" of firmware in case you need/want to go back to an earlier version because of certain new bugs or whatever.

Imaging utilities

Deep Sky Stacker -- free software to process light, dark, flat, flat-dark, different color channel, etc. astro image frames.

Also there's Deep Sky Stacker Live -- completely different program does rudimentary processing "on the fly" for the impatient.

Nebulosity -- handicapped trial version. Unlocked version not free but well priced, excellent astro image processing software. From Craig Stark at Stark Labs.

Cross-generating programs (put crosshairs on your monitor image):

• DSI II Cross -- on-screen crosshairs for DSI II. 
• Here's DSI Cross for the earlier cameras. 
• Another cross-generating utility is JAC Virtual Crosshair.

K3CCDTools -- outstanding software to control Philips 740K, 840K, and SPC900 webcams, along with others. Not free after 30 day trial but highly recommended.. Combined with Registax (below) and a cheap webcam, you can have hundreds of hours of fun imaging brighter solar system objects. Also recommended: get free WcCtrl (below, free) to go with this.

wxAstrocapture -- Free webcam control and capture software for Windows, Linux. New, seems to have bugs for some operating systems.

Registax -- Free software to help stack astro images. Another fine item from Cor Berrevoets, in Belgium. Handles webcam AVIs, also still camera FITS, JPG, TIFF, etc.

Matt Taylor's Imagers Toolkit

QCamLog -- utility that logs webcam settings to a file

QCFocus -- webcam focusing utility

WcCtrl -- similar purpose as QCamLog, above.

WcRmac -- software "raw" mod for Philips webcams

VirtualDub

Avi2Bmp

Iris

Astro-Snap

TeleAuto

FITS viewers / header editors. Ever have to go through a whole pile of FITS images to weed out the bad ones, or check the imaging temperatures to find the correct dark frames? It takes way too long in the Photoshop FITS Liberator plugin. Here's other ways to get in and get out:

• AVIS Fits Viewer Free.
• Fits4Win Free. Allows viewing FITS files and headers from Windows Explorer. I found this to be incredibly buggy, but there ya go...

FITS processors.

• Anybody who uses Photoshop to process FITS images needs the FITS Plugin. Free, from the people at ESA, NASA and Hubble.
• FitsX 21 day trial, then 25 €. More than a viewer; it's a powerful FITS image processor.

Blind astrometry. What is blind astrometry? You feed it a photo of stars, without any other info, and it spits back what it was, possibly when it was. Explanation here. And here.

• Astrometry.net is a blind astronometry solver currently in "alpha" testing. Works on everything but Windows.
• Now it works. You can upload your image to the Astrometry group on Flickr, and the blind astrometry solver will automatically find your image and return its coordinates, orientation, scale (arcseconds per pixel), and a list of objects found in your image. It will also identify the objects by putting boxes around them, which appear when you mouse over the image.
• This can be very handy for checking the plate scale of astrocamera / focal reducer / Barlow setups.

Here's a free software package called Astrometrica that does "plate solutions" (or "plate solves") of astro images. It won't identify a field for you, but it will do lots more, if you already know what's in the field.  

WinJUPOS -- a utility that lets you find the planetary coordinates of features. Works for all planets, Sun, Moon; especially useful for Mars, Jupiter, Moon.

• Download WinJUPOS
• Brief tutorial

Test patterns for checking your cameras and lenses.

• downloadable EIA 1956 test patterns and in PDF form
• a wide EIA chart
• what the heck is modulation transfer function anyway?
  • and his downloadable custom test charts
  • you can even cook up your own but it's horribly expensive

G2V stars for white balance

• Starizona how-to page on G2V balance

Filter transmission curves (large collection of various manufacturers)

Imaging guides / educational / tutorial materials

Matt Taylor's DSI tutorial DVD videos

Meade's own DSI tutorials, presented by Matt Taylor.

Jerry Lodriguss' Photoshop for Astrophotographers book-on-CD-ROM

Ron Wodaski's New CCD Astronomy print book and online resources

Photoshop Astronomy by R. Scott Ireland

Handbook of Astronomical Image Processing by Berry and Burnell. The Bible for amateurs. Includes powerful software package, AIP4WIN 2.0 (with online upgrade, now up to V2.2).

Great info by Richard Crisp on synthetic color imaging through narrowband filters, and lots more

• More details on narrowband imaging
• Crisp's article in S&T
• Image gallery

Jan Timmermans' big site of useful information

• Jan's tutorials gateway
• Jan's equipment gateway. Tons of useful practical info
  • Meade / Coronado PST

Spectroscopy

Astronomical Ring for Access to Spectroscopy

• LHIRES spectrograph
• Kit assembly
• More spectrograph plans from Christian Buill
• Associated Yahoo group

 Spectrashift -- seriously advanced amateur spectroscopy, including radial velocity planet detection

Solar system data

JPL Small-Body Database Browser

• Example: somewhere there's an asteroid with my name on it.

List of minor planet names; maybe there's one with your name on it.

Calsky highly detailed computer-generated views of solar system and deep-space objects. Introduction and personalized setup. Can be set to automatically e-mail alerts for specific events.

Spaceweather has lots of useful info, including snapshot of current sunspots, and list of current near-earth asteroids.

Find Orb -- determine minor planet and satellite orbits from observations.

"Find_Orb can take a set of observations of an asteroid or comet, given in MPC (Minor Planet Center) format or the NEOIBO or AstDyS formats, and find the corresponding orbit...Find_Orb can determine orbits of artificial Earth satellites and for satellites of other planets."

Upcoming asteroid occultations; more detail here.
Also at asteroidoccultation.com

Satellites

Heavens Above. "Register" your location to get personal satellite pass predictions. Free. You can also sign up to get automatic e-mail alerts for various events (auroras, satellites passing across Sun or Moon, etc).

Celestrak Space Track Retriever lets you download fresh orbital data for satellites, to use in skycharting programs

To use that, you'll need to sign up with Space Track for a free user account.

Being the Air Force, they don't want you to get the orbital elements for "classified" satellites. No problem; the Internet leaks like a sieve and you can get them here.

One recurring problem with trying to track the International Space Station is that they keep moving the thing. Orbital burns, corrections, whatever. So often the orbital elements you just downloaded from Space Track are already out of date. One place to get even fresher TLEs is from NASA itself, at this site, along with a log of what maneuvers have been made, when.

The old Satscape, version 2.0.2. There is a new Java-based, all-things-to-all-operating-systems version, but it's horribly buggy. Avoid the Java. (General Satscape page). Again, for this program, you should set yourself up to get fresh Space Track satellite elements, see above.

Heavensat is a Russian satellite tracking program, looks good, good English interface. Doesn't come with extensive documentation but a little exploring, some cutting and pasting of TLE files into the appropriate (well labeled) folder, and it's good to go. Gives quick, excellent overview of what's up, when; then one can use Cartes du Ciel (see section Sky Charting Software) or Satellite Tracker (this section, below) to home in on the target. Free.

Tons of satellite software links

Another page of satellite software links

Idsat download link -- "IDSat assists in the identification of observed satellites, by computing and tabulating close appulses of known satellites relative to the observed time and position. It is conceptually similar to Mike McCants' Findsat program, but provides additional information, and includes various convenience features.

Findsat -- I found that although it has a clumsy DOS command-line and text file based  interface, this works; on the other hand, I couldn't get IDsat (the alternative program, above) to work. 

    German tutorial for Findsat. 

ISS Simulator -- shows how the ISS looks as it's passing over your location. (Now -- early 2008 -- hopelessly out of date).

Brent Boshart's Satellite Tracker. Outstanding software but as of March 14, 2008, Brent has announced that he will no longer be supporting this program. Former website was heavenscape.com . It used to be, you could download the trial version, good for 20 trials, and then pay something like $30 for the unlocked version. The Yahoo support forum for this forum may or may not go away. For now, at this writing, Brent has turned the program loose, and a completely unlocked version 2.4.8 is available for download in the Files section of that group. However, he says other parties are showing interested in the program, and if he sells it to them, they may pull the plug on "free". So get it if you can, while you can. Here are Internet Wayback Machine archived screen shots of Boshart's page before he took it down. (Update) Although Brent Boshart said he'd stop supporting the software with version 2.4.8, he, or somebody, wrote a bug fix called 2.4.9. It can be downloaded from the Yahoo support forum. 

•    Using Satellite Tracker on non-Meade equipment. Yes, it can be done.

 This site, N2YO (I have no idea what it means) is extremely handy for looking up data and history of satellites. You can type in a NORAD number and it will return the data and current location.

 Spaceweather's simple satellite flyby calculator.

 Satevo -- a program to calculate and predict satellite orbit decay and re-entry.

Time, sidereal time, and time setting utilities

Setting your computer clock accurately, to better than one second, is important for many astronomical applications -- for example, satellite tracking. Computer clocks are not intended to be accurate timekeepers, and typically drift as much as several seconds per day.

About Time

Dimension 4

Astronomer's Digital Clock displays local and Greenwich time and sidereal time. CAUTION: this program is 6 years old and does not correctly handle the new Daylight Savings Time rules for USA. You may need to shift on time zone in either direction until the calendar catches up.

Sunclock -- free "World Map" or Geochron type of display, showing sunrise and sunset lines, local times, subsolar and sublunar points, etc.

Julian Date Converter from the U.S. Naval Observatory

Publications

Sky and Telescope Magazine has finally put its index back online. 

• Complete index, 1941-2009, in CSV (comma-delimited spreadsheet, opens in Excel) format (4.4 Mb)

Also available:

• Download the 2000-2009 index in Excel spreadsheet format (1 Mb)
• Download the 2000-2009 index in Text format (600 Kb)
• Download the 2000-2009 index in HTML format (2.7 Mb)

Sky charting software

Cartes du Ciel -- outstanding free software with lots of optional catalogs and plug-ins.

• Best bet:  go to download page and get Complete package 2.76 and then add the Version 2.76c update
• If you have lots of disk space, get the Hubble Guide Star package which will go down to ~ mag. 15
  • Cookbook instructions for how to install the HSC. I didn't have any luck with Winzip, as Winzip needs some special settings set and my ancient version doesn't have that, so I used ZipGenius 6.
• There is a Version 3 but it's still in beta.

Palomar Digitized Sky Survey from Space Telescope Science Institute. Enter object coordinates and field size, it returns a view of that object. Handy for checking framing of images, finding faint background stars for tracking satellites / asteroids, etc.

Sky-Map.org sky charts on the Web; goes down to mag. 19 or so.

Aladin sky atlas -- online atlas from the Strasbourg Astronomical Data Center

Vizier -- astronomical catalog browser from the Strasbourg Astronomical Data Center

Simbad -- astronomical database (literature citations) from the Strasbourg Astronomical Data Center

Overview of the Sharpless Catalog of nebulae

Sky & Telescope Magazine index search

Virtual Moon Atlas

• Several different download versions, from "Light" to "Pro." Free.

Wondering what to look at on the Moon? Here's the Lunar 100. (S&T references are out of date, the series is now complete)

Mars Previewer II shows you which Martian features are facing us at any given time. Download here. Free.

Calsky highly detailed computer-generated views of solar system and deep-space objects. Introduction and personalized setup. Free.

The old JupSat 95 viewer. Free.

Sky & Telescope has a Javascript applet that shows the configuration of Jupiter's moons.

And another for Great Red Spot transits.

Sky & Telescope's Javascript utility for finding Saturn's moons

Planetary Nebulae

Planetary Nebulae Gallery
Paul and Liz Downing's list of nebulae
Atlas of the Universe list of planetary nebulae
Wikipedia list of planetary nebulae
Planetary Nebula Image Catalog