About & Pics


As featured in Astronomy Now and Sky At Night Magazines!

Double Stars is an astronomy app for hunting down and resolving the beautiful double stars throughout the night sky. The app features a catalogue of hundreds of known double stars, and will identify for you which ones you will be able to see, and when, based on your location and viewing equipment. You can then take the app out into the field to help you locate the double star and record a successful sighting.

Here's what our beta testers told us about the app:

"Great app and I'm loving the filter functions. It makes it so easy for me to decide my targets for the night!"

"What a wonderful app. I had a brilliant time last night seeing double stars in Leo and Bootes, mostly new and some old friends"

"a great app, well designed interface and a unique use for the iPhone's accelerometers and GPS"

Interested? Please read on...

Double star spotting is a pursuit everyone can enjoy with the just the naked eye or with advanced telescope equipment. For centuries, astronomers have enjoyed tracking down these objects and testing their eyes and the limits of their equipment.

Double Stars has a detailed catalogue covering both hemispheres and all 88 constellations. The catalogue covers the key data for double stars; the magnitudes of the pair, the separation of the pair, the positive angle and the location in the night sky. It also notes stars with colour variations and those that form part of a multiple system for 3 or more stars.

Using your location, the time and date, and the details of your observing equipment, the app will filter the catalogue, creating a bespoke list for your location and equipment.

"Smart Tours" automatically create lists of the best doubles each night; your favourites, colour doubles, multiple systems, wide easy pairs, tough split pairs or by constellation. In addition, you can create your own tour.

Out in the field, the app operates in a special night mode allowing you to use it without ruining your dark adapted vision. All the key information you need is present – Double Stars even suggests an eyepiece to obtain the best magnification.

The app also features live Alt Azimuth tracking of the double star for those without GoTo equipment, and uses the inbuilt compass and gyroscope (where available) to point you in the right direction! Try attaching your iPhone to your telescope for precision control. The Sky Tour allows you to record which stars you have resolved. You can add the best double stars to a favourites list for later.

As the seasons change, revisit the night sky each month with Double Stars to see the pick of the delights of each constellation.

We really hope you’ll enjoy discovering and resolving new double stars with this app.

 $0.99 in iOS App Store


Double Stars screenshot 1Double Stars screenshot 2Double Stars screenshot 3Double Stars screenshot 4

Version History

Launched Apr 05, 2012 (over 6 years ago).

Releasing new versions every over 1 year, on average.

Jun 06
Version 2.0.1

Adds the ability to select which data sources make up your star catalogue

Sep 19
Version 2.0.0

Revised and updated for modern devices and operating systems, with a new look and tons of new doubles for you to enjoy! Thanks so much for everyone that emailed requesting we update the app, without that we probably would have just let it quietly die.

Oct 12
Version 1.2

* iOS6 and iPhone 5 Support
* Catalogue corrections
* Fix to the visibility algorithm for Southern Hemisphere (thanks Murray!)

May 17
Version 1.1

- Corrected some errors in the catalogue
- Fixed a bug where the relative magnitudes of stars were not displaying correctly in the sky tour
- Fixed a bug with stars with a declination between 0 and -1 degrees
- Changed the visibility calculation to only use the exact time of the sky tour rather than a window of 6 hours

Apr 05
Version 1.0

Previous 3 versions


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