Online Tools

Classical

• Wolfram Alpha^(€): Mathematics (including complicated things :)), looking up facts, converting units (which Google also can do), etc.
• Colour brewer: Some curated nice and clear schemes for maps (2D plots) but also finite numbers of curves
• Filter Profile Service of the Spanish Virtual Observatory: Filters (for photometry) for any instrument on any telescope…
• Theoretical spectra: Spectra for planets and stars from maaaany different models
• Webplot Digitizer: Extract data from plots

AI-based

• ChatAI^🎓 of the Academic Cloud with many different LLMs (see also the portal)
• Claude
• Writefull^€, integrated into Overleaf

Literature research

• NASA/ADS with searches of papers citing a certain work: citation(bibcode:…)
• Web of Science/Science Citation Index Expanded^🎓

Notes

€: premium/pro account necessary for serious work
(€): premium/pro account possible, serious work can still be done with free version
🎓: payed for by the university, needs UDE login

From the FAQ page at Wolfram|alpha (the service is some 20 years old!):

"Does Wolfram|Alpha use artificial intelligence?

Not in a traditional sense. Wolfram|Alpha isn't mainly based on emulating human reasoning. Instead it uses powerful methods from science and algorithmic computation to get directly to answers."

"Is Wolfram|Alpha an artificial intelligence?

It's much more an engineered artifact than a humanlike artificial intelligence. Some of what it does—especially in language understanding—may be similar to what humans do. But its primary objective is to do directed computations, not to act as a general intelligence."