An open source astronomy dashboard (https://caelus.siderealcode.net)
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Hello HN! My name is Rémy and I recently published an astronomy dashboard where everything is open source: the code of the website, the framework it is based on and the library that computes astronomical data.For the last few years, I have been developing the Ruby library Astronoby (https://github.com/rhannequin/astronoby) with as much dedication and perseverance I could while I don't have any scientific academic background. My end goal was to use this library and build a website that not only provides as much data as possible, but let anyone access and understand how it was computed. This goal is on its was of completion with Caelus.Of course the website is still quite new and there are many features I will implement in the coming weeks and months, including the ability to set any date, having a global view of the Solar System, having an interactive sky chart, a tool to prepare your observation night, having the website in multiple languages, etc.I believe astronomical data should be universal and anyone should be allowed to easily access this data, manipulate it, understand how it was generated, and contribute to and with the community.My goal is to make this project truly collaborative. I am open to feedback, ideas, requests, bugs, everything, to offer the community open source astronomical data.Thank you all.Website: https://caelus.siderealcode.netSource code: https://github.com/rhannequin/caelus
HN · launched Nov 10, 2025 · 5 upvotes (top 90%) · 0 views
Niche: stargazing and astronomy weather apps · 90 launches, 12 in the last 7 days ▼ -29% · Explore this niche →
Category and tags
- Horizontal
- Analytics & BI
- Prosumer
- Not AI
- Hobby / open-source project
More like this: all 90 launches in stargazing and astronomy weather apps →
Could you build this?
Partial The web dashboard and visualizations can be easily vibe-coded, but high-precision astronomical calculations require specialized celestial mechanics algorithms and ephemeris tables.
What it would actually take: The front-end can be built with React/Next.js and charting/planetarium canvas libraries, but the backend requires precise astronomical calculation engines (like VSOP87, ELP2000, or SPICE kernels) to calculate ephemerides, celestial coordinates, and nutation/precession corrections. A developer must either implement or integrate complex celestial mechanics libraries and maintain reliable time standard conversions (UTC, TAI, TT).
Discussion
3 comments analyzed.
Competitors mentioned: Swiss Ephemeris, JPL Development Ephemeris (DE), IMCCE INPOP
Concerns raised: Data not particularly new/current
Competitors
Other products that read as similar to this one : 223 launches clear the similarity bar, closest 8 shown.
Attention rank: #220 of 224 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 12 days after the earliest competitor.
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