0.6: Team Size Doubling + iObserve on the web ! 0.6: Team Size Doubling + iObserve on the web !

This is a milestone for Arcsecond ! I am happy to announce that Eric Depagne, currently astronomer at SAAO/SALT has agreed to join his forces to His expertise with Python will help a lot on the backend, but I don't expect him to remain within the boundaries of it! 

Moreover, we releases iObserve on the web ! Not as feature-rich as the macOS app yet. But already new features that will belong only to Arcsecond: Night Logs (in prep) and Data !

Freely regsiter in and tell us what you think !

 iObserve on the web

iObserve on the web

iObserve on the web is coming

iObserve on the web is coming

Well, winter is already there, anyway. So now, iObserve is coming ... on the web. #GameOfCurves

For those who don't know yet, iObserve on the web is called You can already checkit out here.

I am very proud of the progresses. But there is a lot to iron out (I had to work on various API endpoints to make it work: /observingsites, /observingruns, /nightlogs, /observations, /users, /telescopes).

But I can't wait to share with you a (debug) screenshot of the current state of it on my machine. Feel free to spread the word!

My blog is my code (quick updates)

I should take the time to annouce a bit more often the releases of my various softwares. But software is a mean of expression by itself, in my humble opinion, when practiced everyday. Don't you read software? ... My blog is my code, and this blog is my secondary blog, talking about the first one.

Anyway, please be aware that is progressing well. It isn't still ready for a full-blast communication pushed into professional tubes though. But time will come.

In particular, note the fusion of the Objects and Exoplanets page (which are kinda of object, aren't they?...). It makes the navigation a lot easier. Moreover, Exoplanet Transits have been also added. Pretty nice. Screenshot below, but judge by yourself directly in this example.

 Yes, I usually look for icecream colors for the beta banner... Don't you like this Strawberry-Pistache ?

Yes, I usually look for icecream colors for the beta banner... Don't you like this Strawberry-Pistache ?

Moreover APIs are slowly maturing, and some API endpoints are now in pretty good shape. Obviously that includes /observingsites, /objects and /exoplanets. I am working full-speed on /observingruns and /nightlogs right now. But /datasets is also pretty nice already (although not yet complete).

To follow all the progresses see my third blog... the changelog

In the meantime, I also released a small update of SwiftAA (v2.0.1) to fix some warnings, making sure it is fully compatible with latest Xcode, and applied a small bugfix about the visibility of a special method (that should be kept internal for that matter). Check it out on GitHub!

I am also busy with new adventures for real professional activities this time. But I tend to usually mutualise the benefits, to increase the pace of releases.

Oh by the way, I am preparing a link between and iObserve ! It's time for iObserve's users to submit new observatories and observing sites not in the app but rather in They will further be importable inside the app. It will be great. The benefit is that: it is not manual anymore (which is good for me), but is directly accessible and shared with everybody !

iObserve v1.6.1

iObserve v1.6.1 just submitted to the Store. I couldn't really find a fix for the rdar problem mentioned earlier. I did modify a little thing in the code that could possibly help. But Apple didn't respond to my inquiry on the subject. I have a user report saying that the problem went away apparently on macOS High Sierra (10.13).

SwiftAA 2.0

SwiftAA 2.0

SwiftAA, the most comprehensive collection of accurate astronomical algorithms just reached v2.0! This is the first version of complete Solar System APIs with units safety and a whopping 90%+ of unit tests coverage.

I am very proud of the result. Lots of things remain in the pipe for an even more amazing v3, but here you have: a complete set of easy-to-read and documented APIs to compute everything you need about the solar system. 

New Builtin Observatories: Hundreds and Counting...

New Builtin Observatories: Hundreds and Counting...

It's been a while now that I chose to make my app iObserve free for all (both on macOS and iPad) and to support it at the basic level (I know iObserve on iPad hasn't received yet the update it deserves). If you don't know why, you should read this.

But of course, it keeps thriving! And a lot of people use it! And one of the best channel I have to get a sense of how often it's being used is the mails I receive to include new builtin observatories. Check this out only for this summer:

Screen Shot 2017-09-01 at 13.29.35.png

It is really warm feeling to see this. 

But if you follow this blog, you also know that I am developing arcsecond,io and that it has a dedicated observatories page, right?

Of course, the obvious thing to do is to plug into iObserve to make it easier for everyone to contribute! And this is what I planned in the past to do, but in the v2.0 of iObserve... which is stalled, because I develop Arg! 

Enough cheating. This blog post is to announce I will develop an update of iObserve 1.6 to use the observatories in That is, I will not wait for v2 of iObserve. The tricky part is that the ObservatoryManager is something essential of the app, and I can't develop this overnight. But enough said, and back to work!



A fantastic meteor iOS app (based on SwiftAA)!

Collaborative work help great developers to push their own ideas forward. Alexander Vasenin participated to key improvements of SwiftAA, put in place by yours truly. SwiftAA, based itself on AA+ by PJ Naughter, but with much easier and swifty APIs, is the most comprehensive and accurate collection of astronomical algorithms in Swift (and Objective-C along the way).   

Alexander just released a wonderful and very detailed iOS app about meteors, called MeteorActive. Find everything about these beautiful phenomena in a snap, thanks to this carefully crafted app. And it's free!

Download MeteorActive ! 


Batch of small updates from the software dpt.

I may not update this blog very often, but things keep moving forward!

First, I've fixed an important bug in SwiftAA, the iOS/macOS framework of astronomical algorithms. There was a confusion on ecliptic coordinates, which was then propagating to other coordinates, and making impossible to have reliable times of Rise, Transit and Set for celestial objects. What a pity if you couldn't compute these times with SwiftAA! It is now fixed. Check the release. Even if it takes time, I keep moving forward to reach the 2.0 milestone.

The other updates are about I made progresses in many compartments: Datasets, Night Logs, Observing Runs, Profiles. Objects page, Publications etc etc. The new root page now has a Google-like search field. For the exoplanets side, I'm working on something very cool, but it isn't ready yet (planned for v0.3).

You can check the changes and the improvements brought by every release in the dedicated Changelog page.

As for iObserve, I keep receiving new observatories. Thanks to all. I may consider an update of iObserve to use observatories in once back from vacations. Better not promise anything though, I know how it goes... 


iObserve night colors on!

Does it sound familiar? I got iObserve night colors drawn on my shiny new night log page of You easily guess what I am heading at! #milestone

Screen Shot 2017-05-06 at 09.50.23.png

Two hours later...

A whole new dimension...

... of the answer to the question about "life, the universe and everythig."


It reminds me the idea that if you ask a horse to draw a god, it will draw a horse.  

Anyway I am surprised I discover this about "42" so late. 

Teasing on Observing Runs...

As announced a few days ago, the Observing Sites page is back online. It is a very basic and functional page for now. There are still a few things in the Javascript Framework I use (Vue.js) I need to explore. In particular: the possibility to edit and add observing sites isn't yet available.

But here is something I am busy with right now: Observing Runs, for which I needed Observing Sites. Looks like a online version of iObserve... 

A very first selection of an observing site inside the Observing Runs dashboard.

I know, I am building again a 3-columns-with-topbar layout... But I think this is clearly the most adapted to a pro app like that. More to come soon! 

Coming soon, a new Observing Sites page on

I am actively working on and there is a lot going on behind the scene. One thing is new though: I start to enjoy front-end dev for the first time (you know, the mix of html, javascript and css), thanks to the excellent framework Vue.js.

Coming very soon, a brand new observing sites page! Stay tuned.

iObserve 1.6.0 submitted to the AppStore

After many months, I finally managed to submit a new version of iObserve. I am happy to see I continue to be able to improve it (even if I am not writing Objective-C code anymore regularly). I also hope it will be good enough for the coming weeks, as I am preparing more stuff for the future!

Making an auxiliary app about Observing Sites...

Making an auxiliary app about Observing Sites...

... on the road to iObserve 2!  

As you certainly know if you read this blog a bit, here and especially here, I am preparing, slowly, a version 2 of my famous app for astronomers: iObserve. One key thing about it are observatories, over and over again. The problem of managing different places, being able to record your own places, possibly sharing them etc, exists since the inception of the app, when it was only in a widget form... 

In the course of the years, I've developed a lot of things about it and never found it entirely satisfactory. Then came was first intended to be the backend for a much lighter iObserve client. But it appears it can solve a lot of things! And the first thing it can solves is to be the one-place-to-go for everything about observatories in the world. 

Hence, one of the primary mission of is to record, store, share, make available all the information about such places.

And the only way to correctly develop, test, bullet-proof the observing sites at is to build an app, using the arcsecond.swift and SwiftAA sdks. So here it is, for the visible part:

Of course, as soon as it gets ready to edit and display useful things about all observatories, and you can add your own etc, you'll get your hands on it! 



Closing sources of for now

I've decided to close the sources of for now. It's been quite a while since I started to think about it.

Two main reasons. First, the opening of the sources had strictly none of the expected effects, that is, to gather people around the project, even just a few. None. Second, is a fairly large project, some said too much. And before I find a satisfactory plan of splitting / simplification / whatever, I prefer to make my business on my own.

However, if anyone is interested to really participate, I'll be happy to include him as a member of the GitHub project.

One small step for a developer...

One small step for a developer...

... but quite a milestone in my master plan (see previous post). After about a year of (discrete periods of intense) work, I've decided that SwiftAA, the best collection of astronomical algorithms on Swift, hit the 2.0-alpha stage.

SwiftAA is intended to be the underlying code framework of all scientific computations of the next version of iObserve. With it, I'll be able to provide tons of details about many objects, and especially about Solar System objects, which are clearly missing in the current app.

It's an alpha stage, of course. It means a lot of details need to be polished: iOS version polishing, more unit tests, a more consistent handling of numeric types etc. But all of the C++ code is wrapped in Objective-C(++) code, and all that old-style code mimicking the original AA+ one is now "Swifted". That is, it has been elevated to a lot higher level of expressive formulation.

Complexity remains, since the solar system isn't quite easy to simplify. Hence, when one has the goal of minimizing the amount of lines of code, to extract the most of it, things aren't easy to read at first. 

But there is a Swift Playground for those interested to learn. I wish I had more time for making this Playground more "ready to use". But as for now, you need to dive a bit into the thing and the project to actually understand it. But time will come, I'll prepare a better one.

In my website stats, I noticed that some people keep talking about iObserve, which is great. One post however mentioned the wish to have a Linux version of it. Those interested in what happens here @ probably understood that it is also part of the master plan. But current web-based technologies to make cross-platforms apps are difficult to put in place. I've tried about 6-7 times. But I don't give up! 

I've received about 30 new observatories to be included in the next version of iObserve. That's really great, as it is the sign of a strong usage of the app (more than 15k downloads so far). They are all in my list of to-dos, but I must say that it is sometimes hard to be motivated to finish this new new version, and I am late. But it will come! 


Master plan of the software department @

Master plan of the software department @

Software is amazing, because it let you create your own world. This is the world as I see it in the future. I learned so much by creating iObserve (over the course of the past years...). And as in science, the main lesson was that I didn't know much actually... 

Hence, since I love challenges, I decided to dive into new questions:

  • new language for the app iObserve
  • new architecture for the app
  • own backend service with specific language
  • start cloud service with storage and online DB
  • extract as many macOS components from app into open-source libraries
  • finally implement dreamed features (night logs, observation simulator...)
  • I'm sure something is missing... 

If someone want to share the bumps ahead on the road, he|she is most welcome.

Clear skies to everyone!

P.S. By the way, just migrated to Python3...