The Silence of the Damned
For those of you who have been bothered by my absence over the past few months, here’s the deal…
Happy Birthday iLanga, Inc.
iLanga, Inc. turns 20 years old today. A little history lesson for your reading pleasure…
Advanced Features: Double Star Orbits
[Update: This will be a regular feature in V2.2, not an “advanced” feature]
Double (or multiple) star systems are not static. The primary and secondary stars typically move with respect to each other. These relative movements can be extremely small (i.e. they don’t appear to move over a period of decades or longer), or they might move relatively rapidly (with noticeable relative motion over a period of months or years). The double star catalogues, and in particular the Washington Double Star (WDS) catalogue, typically only show a single instance or snapshot of relative position (separation and position angle) for each object, which might be quite out-of-date (some even 100+ years out of date).
Many such star systems have been observed and the relative positions of the stars noted over an extended period, allowing the actual orbits of the stars to be estimated. A new feature in the Advanced version of AstroPlanner allows you to see those orbits and estimate the current relative positions of the stars.
Advanced Features
I have been pondering having an “Advanced” version of AstroPlanner containing various features only of interest to more advanced users. There would be an extra fee for these features to be enabled. Here’s some of my thinking on the matter.
“Splitability” for double-star observers
Recently, one of my AstroPlanner users, Wilfried Knapp, posted this message:
On the CN DSO forum is a rule of thumb for splitting double stars in discussion: Multiply delta-m (if less than 1 then set 1) with the Dawes limit of your scope to get the minimum separation you need to split this double star under otherwise excellent conditions (seeing etc.).
This rule would be nice if available as wizard or better as option when searching double star catalogues.
This seemed like a perfectly useful and easy-to-implement way of rejecting double stars that will not be splittable through a particular telescope, even under perfect conditions. So I decided to integrate it into V2.1.
2012 09 01
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The sadness of rejection
AstroAid V2.0 was rejected by Apple this morning. Sigh. The fix took about 3 minutes, and the app is now back to “waiting for review”. i.e. another 10 days of waiting. Continue on to read about the fix, or stop right here if you’re not a geek.
AstroAid V2
Introducing AstroAid V2. Yes, the version number has been bumped because the changes are many, and the app looks quite different. Let’s look at what’s new and changed. I will illustrate the iPad version, but the iPhone version has all the same features – just in a somewhat different interface.
I will be handing the finished app to Apple for approval in the next day, so it should be available for download in a week or so.
Image quality
I have been asked on several occasions about the image quality setting in Image Preferences, and what effects it will have. To make things a bit clearer I have implemented a feature in V2.1 that compares the effect of saving DSS images at less than 100% quality. The results are quite revealing, even for me.
Constellations
For AstroPlanner V2.1, constellations become full citizens in the object list. This enables some interesting features.
More AstroPlanner V2.1 features
I have been working on a couple more V2.1 features, described briefly here. These are features to search for plan documents on disk, improve the Plan Creation Wizard, and support upcoming catalogues.
Hopefully this will help assuage the fears of some folk who think I’m working full-time on iOS apps.