Model reference · open weights

aion

LLMs polymathic-ai Omni (any→any) 1 build Open weights 2k dl/mo

aion is an open-weight language model from polymathic-ai. aion-base (FP32) weighs 636 MB; the smallest configuration that runs it is RTX 3060 12 GB.

For self-hosting, compare this build's requirements below with the GPU you plan to rent.

  • AION-base is a 318M parameter omnimodal model developed by Polymathic AI for astronomical surveys.
  • It integrates 39 distinct data types, including imaging, spectra, and catalogs, to support adaptation to various astronomical tasks through multimodal masked modeling.
  • The model uses an encoder-decoder transformer architecture and is released under the MIT license.

Summary of the polymathic-ai/aion-base model card, 2026-10-01

What it is

Released bypolymathic-ai
Released2025-05-16
Parameters318M
VRAM636 MB for the weights

What it runs on

Memory and cards for aion-base (FP32)

636 MBweights, file size
762 MBruntime overhead, at least

How much memory each request adds isn't estimated yet for this architecture. The weights need at least the cards below, plus room for the context.

CardWeights alone
RTX 3060 12 GBfits
RTX 4060 Ti 16 GBfits
RTX 3090 24 GBfits
RTX 4090 24 GBfits
RTX 5090 32 GBfits
L40S 48 GBfits
A100 80 GBfits
H100 80 GBfits
RTX PRO 6000 Blackwell 96 GBfits
DGX Spark (GB10) 128 GB unifiedfits
H200 141 GBfits
B200 180 GBfits

From the model card

What polymathic-ai says about aion

Read the model card

AION-base is a 300M parameter large omnimodal model specifically designed for astronomical surveys, presented in the paper AION-1: Omnimodal Foundation Model for Astronomical Sciences. It integrates 39 distinct astronomical data types and enables adaptation to a wide range of astronomical tasks through multimodal masked modeling.

Project Homepage: https://polymathic-ai.org/

Model Details

  • Architecture: Encoder-Decoder Transformer (12 blocks each, 768 dim, 12 heads)
  • Parameters: 300M
  • Training: Multimodal Masked Modeling (4M) on astronomical survey data
  • Modalities: 39 data types including imaging, spectra, catalogs, and photometry

Installation

Assuming you have PyTorch installed, you can install AION trivially with:

pip install polymathic-aion

For advanced installation options, including specific PyTorch versions or developer installations, refer to the GitHub repository.

Usage

After installation, you can load the pretrained model and start analyzing astronomical data.

import torch
from aion import AION
from aion.codecs import CodecManager
from aion.modalities import LegacySurveyImage, Z

# Load model and codec manager
model = AION.from_pretrained('polymathic-ai/aion-base').to('cuda')  # or 'aion-large', 'aion-xlarge'
codec_manager = CodecManager(device='cuda')

# Example: Prepare your astronomical data (e.g., a dummy Legacy Survey image)
# In a real scenario, 'your_image_tensor' would come from your dataset.
your_image_tensor = torch.randn(1, 4, 96, 96) # Example: batch_size=1, 4 bands, 96x96 resolution
image = LegacySurveyImage(
    flux=your_image_tensor,
    bands=['DES-G', 'DES-R', 'DES-I', 'DES-Z']
)

# Encode data to tokens
tokens = codec_manager.encode(image)

# Option 1: Extract embeddings for downstream tasks
embeddings = model.encode(tokens, num_encoder_tokens=600)
print(f"Extracted embeddings shape: {embeddings.shape}")

# Option 2: Generate predictions (e.g., redshift)
# For this example, we predict redshift (Z) from the image.
# The target_mask tells the model which modality to generate.
preds = model(
    codec_manager.encode(image),
    target_modality=Z,
)
print(f"Predicted redshift logits shape: {preds['tok_z'].shape}")

Supported Data Types

AION-Base processes data from major astronomical surveys. Here's an overview of the supported categories:

CategoryDescriptionToken Name(s)
Imaging (2)Legacy Survey, HSC Widetok_image_ls, tok_image_hsc
Catalog (1)Legacy Survey catalog entriescatalog
Spectra (2)SDSS, DESItok_spectrum_sdss, tok_spectrum_desi
Gaia (4)BP/RP spectra, parallax, sky coordstok_xp_bp, tok_xp_rp, tok_parallax, tok_ra, tok_dec
Gaia Photometry (3)G/BP/RP fluxtok_flux_g_gaia, tok_flux_bp_gaia, tok_flux_rp_gaia
Legacy Survey (9)g,r,i,z bands & WISE W1–W4 flux, E(B–V)tok_flux_g,…,tok_flux_w4, tok_ebv
Legacy Shape (3)Ellipticity components & effective radiustok_shape_e1, tok_shape_e2, tok_shape_r
HSC Photometry (5)g,r,i,z,y magnitudestok_mag_g,…,tok_mag_y
HSC Extinction (5)g,r,i,z,y extinctionstok_a_g,…,tok_a_y
HSC Shape (3)Shape components 11,22,12tok_shape11, tok_shape22, tok_shape12
Other (1)Spectroscopic redshifttok_z

Resources

  • GitHub Repository: https://github.com/PolymathicAI/AION

License

This project is licensed under the MIT License. See the LICENSE file in the GitHub repository for full details.


Built with ❤️ for the astronomical community by https://polymathic-ai.org/

Quoted from the model card on Hugging Face. The full card is behind the Hugging Face link above.

How it works

How language models work

Your prompttext / messagesTransformerattention over tokensNext-token loopgenerate + streamResponsetext · tool callsA language model reads your tokens and predicts the next one, again and again, streaming the reply back.
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