# RA/Dec - AZ/Alt — Right Ascension & Declination

> Astronomical coordinate conversion and sidereal time clock for telescopes. (iPhone/iPad app by Claude Johnson.)

- Source: https://appshunter.io/ios/app/radec-azalt/id1469870275 (this page in markdown: same URL + `.md`)
- Developer: [Claude Johnson](https://appshunter.io/developer/1441385712)
- Category: Utilities
- Price: Free
- Rating: 3.30/5 from 3 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.0 · 29 MB
- Languages: American English
- Released: 2019-07-23
- Data updated: 2026-08-09
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/radec-azalt/id1469870275/reviews.md

## What is RA/Dec?

It's 2 apps in 1
1. Local Sidereal Time Clock
2. Convert the Right Ascension and Declination of any celestial body into its Hour Angle and Declination for a telescope with an equatorial mount and into Azimuth and Altitude for a telescope with an altazimuth mount

## Key features

- Local Sidereal Time Clock
- RA/Dec to Hour Angle/Declination conversion
- RA/Dec to Azimuth/Altitude conversion
- Equatorial mount support
- Altazimuth mount support

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/radec-azalt/id1469870275/reviews.md

### 5/5 — Very practical tool to find stars from chart coordinates

*2021-06-29*

I recently got a basic star tracker. I found It can be difficult to find objects visually. 
To aid in finding objects of interest I tried the following and it worked quite well.
After alignment of my tripod + tracking mount to the celestial pole, I adjust my pan and tilt head positions on the tracker. Setting pan angle to 0degrees. ( note, you could also use a ball head but its harder to set altitude later ) Adjust tilt on the head until my camera lens is pointing at Polaris. If the tracker is aligned to the pole then the tilt should be approximately 0degrees. 
Now look up a star chart and find your objects RA and declination. Punch those numbers into this app. The altitude and azimuth numbers provided by the app can then be applied to the pan angle and altitude (with current latitude of your location subtracted). 
Your camera should now point in the  direction of the desired celestial object. 
 Simple and effective solution. 
Thanks for a great little App.

### 1/5 — Don’t bother

*2020-01-19*

For one, it forces Location Services ON. That makes my objective — determining Az and Alt for another location — rather difficult. (Read:impossible) For another, totally unresponsive to user input, with exception of help buttons. OK, fine; I didn’t want to enter Lat and Long anyway. Last, tiny white font on bright green bckgrnd is really, really difficult to read.  Right after I post, I’m deleting it.

## Frequently asked questions about RA/Dec

### What is RA/Dec - AZ/Alt used for?

RA/Dec - AZ/Alt is used to convert celestial coordinates (Right Ascension and Declination) into values suitable for aiming telescopes. It provides Hour Angle and Declination for equatorial mounts, and Azimuth and Altitude for altazimuth mounts.

### Does RA/Dec - AZ/Alt have ads?

No, RA/Dec - AZ/Alt is ad-free, allowing for an uninterrupted user experience.

### What devices is RA/Dec - AZ/Alt compatible with?

RA/Dec - AZ/Alt is compatible with iPhone, iPad, and iPod touch devices.

### How often is RA/Dec - AZ/Alt updated?

RA/Dec - AZ/Alt was last updated on July 23, 2019, with version 1.1.0. The current update frequency is not specified.

### What is the age rating for RA/Dec - AZ/Alt?

RA/Dec - AZ/Alt has an age rating of 4+, making it suitable for a wide range of users.

### What is the user rating for RA/Dec - AZ/Alt?

RA/Dec - AZ/Alt has an average rating of 3.3 stars based on 3 user ratings.

### Can RA/Dec - AZ/Alt be used offline?

The description does not specify offline capabilities, but astronomical calculations typically do not require an internet connection.

### Is RA/Dec - AZ/Alt free to download?

Yes, RA/Dec - AZ/Alt is available for free download.

## Version history (last 1 release)

### 1.1.0 — 2019-07-23

No release notes.

## More apps by Claude Johnson

- [Write abc](https://appshunter.io/ios/app/write-abc/id1441385713)
- [Sol's system and its neighbors](https://appshunter.io/ios/app/sols-system-and-its-neighbors/id1454193459)
- [Virtual telescope](https://appshunter.io/ios/app/virtual-telescope/id1470830440)

All apps by Claude Johnson: https://appshunter.io/developer/1441385712

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-09.*