README.md

---
license: mit
---

# MMT Snapshot

Snapshot of MMT[^1] database.

Last update: May 2025

## File structure

- `rso.csv` - object information
- `data/` - directory containing tracks measurements in `.parquet` files
- `bulk_idx.txt` - contains the index of last bulk file downloaded from the MMT database

## Object information

- `mmt_id` - Identification number of the object in MMT database.
- `norad_id` - Norad identification number of the object.
- `name` - Name of the object.
- `country` - Country of origin.
- `variability` - Variability: "non-variable", "aperiodic", "periodic".

## Tracks measurements

Parquet files are structured with the following fields:

- `id` - Identification number of the record.
- `norad_id` - Norad identification number of the object.
- `period` - Apparent rotational period in seconds.
- `timestamp` - Start of the observation timestamp in the format '%Y-%m-%d %H:%M:%S'
- `name` - Name of the object.
- `variability` - Variability: 0 (nonvariable), 1 (aperiodic), 2 (periodic).
- `time` - A list of observation times.
- `mag` - A list of measured standardized magnitudes to 1000 km distance.
- `phase` - A list of measured phase angles in degrees.
- `distance` - A list of measured altitudes in km.
- `filter` - A list of filters used: 0 (uknown), 1 (clear), 2 (pol), 4 (V), 8(R), 16(B).
Tracks measurements are stored in `.csv` files with containing the following fields: time,stdMag,phase,distance,filter.

## 📝 Citing

```bibtex
@article{kyselica2025lcdc,
  title={LCDC: Bridging Science and Machine Learning for Light Curve Analysis},
  author={Kyselica, Daniel and Hrob{\'a}r, Tom{\'a}{\v{s}} and {\v{S}}ilha, Ji{\v{r}}{\'\i} and {\v{D}}urikovi{\v{c}}, Roman and {\v{S}}uppa, Marek},
  journal={arXiv preprint arXiv:2504.10550},
  year={2025}
}
```

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[^1]: Karpov, S., et al. "Mini-Mega-TORTORA wide-field monitoring system with sub-second temporal resolution: first year of operation." Revista Mexicana de Astronomía y Astrofísica 48 (2016): 91-96.