Update GCVS variable stars: 60,894 stars

README.md

@@ -3,7 +3,7 @@ license: cc-by-4.0
 pretty_name: "General Catalogue of Variable Stars (GCVS)"
 language:
   - en
-description: "The canonical catalog of variable stars maintained since 1948 by the Sternberg Astronomical Institute, Moscow. Sourced via VizieR CDS Strasbourg."
+description: "The General Catalogue of Variable Stars (GCVS) is the canonical reference catalog of variable stars, maintained since 1948 by the Sternberg Astronomical Institute at Moscow State University.  Variable"
 task_categories:
   - tabular-classification
 tags:
@@ -27,64 +27,44 @@ configs:
 
 # General Catalogue of Variable Stars (GCVS)
 
-*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) collection on Hugging Face.*
 
-![Update GCVS](https://github.com/juliensimon/space-datasets/actions/workflows/update-gcvs.yml/badge.svg)
-![Updated](https://img.shields.io/badge/dynamic/json?url=https://raw.githubusercontent.com/juliensimon/space-datasets/main/status.json&query=$.gcvs&label=updated&color=brightgreen)
+<div align="center">
+  <img src="banner.jpg" alt="The Crab Nebula, a supernova remnant" width="400">
+  <p><em>Credit: NASA/ESA/Hubble</em></p>
+</div>
 
-The General Catalogue of Variable Stars (GCVS) is **the** canonical reference catalog of variable
-stars, maintained since 1948 by the Sternberg Astronomical Institute at Moscow State University.
-Currently **60,894** variable stars with 544 variability types.
+
+*Part of a [dataset collection](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) on Hugging Face.*
 
 ## Dataset description
 
-Variable stars are stars whose brightness changes over time, either due to intrinsic physical
-processes (pulsation, eruption, rotation) or extrinsic geometry (eclipsing binaries). The GCVS
-is the internationally recognized authority for variable star designations and classifications.
-It has been compiled and updated for over 75 years, serving as the foundation for stellar
-variability research.
-
-Each entry includes the GCVS designation, coordinates, variability type, magnitude range,
-period, epoch of maximum, and spectral type where known.
-
-The catalog spans an extraordinary range of stellar physics. Mira variables (type M) are
-asymptotic giant branch stars with periods of hundreds of days and visual amplitudes exceeding
-2.5 magnitudes, driven by radial pulsations in their extended hydrogen envelopes. Semi-regular
-variables (SR) occupy a similar evolutionary stage but pulsate with smaller amplitudes and
-less predictable cycles. Eclipsing binaries (EA, EB, EW) are not intrinsically variable at
-all -- their brightness changes arise purely from orbital geometry as one star transits the
-disk of its companion. At the other extreme, eruptive variables like UV Ceti flare stars and
-FU Orionis objects undergo sudden, dramatic outbursts linked to magnetic reconnection events
-or disk accretion instabilities.
-
-Among the most scientifically important classes are the pulsating variables used as standard
-candles: classical Cepheids (DCEP), whose period-luminosity relation underpins the
-extragalactic distance ladder, and RR Lyrae stars (RR), horizontal-branch pulsators that
-trace the old stellar populations of the Galactic halo and globular clusters. The GCVS
-classification scheme, refined over decades, remains the basis for variable star taxonomy
-worldwide, and GCVS designations are the official IAU-recognized names for variable stars
-not already named in the Bayer or Flamsteed systems.
-
-Because the GCVS draws on over a century of photometric monitoring, it captures variability
-on timescales inaccessible to modern surveys that have operated for only a few years. Many
-entries include epochs of maximum light stretching back to the early twentieth century,
-enabling studies of period changes, evolutionary effects, and long-term amplitude modulation
-that would be impossible from any single contemporary survey alone.
+The General Catalogue of Variable Stars (GCVS) is the canonical reference catalog of variable stars, maintained since 1948 by the Sternberg Astronomical Institute at Moscow State University.
+
+Variable stars are stars whose brightness changes over time, either due to intrinsic physical processes (pulsation, eruption, rotation) or extrinsic geometry (eclipsing binaries). The GCVS is the internationally recognized authority for variable star designations and classifications. It has been compiled and updated for over 75 years, serving as the foundation for stellar variability research.
+
+The catalog spans an extraordinary range of stellar physics. Mira variables (type M) are asymptotic giant branch stars with periods of hundreds of days and visual amplitudes exceeding 2.5 magnitudes, driven by radial pulsations in their extended hydrogen envelopes. Semi-regular variables (SR) occupy a similar evolutionary stage but pulsate with smaller amplitudes and less predictable cycles. Eclipsing binaries (EA, EB, EW) are not intrinsically variable at all -- their brightness changes arise purely from orbital geometry as one star transits the disk of its companion. At the other extreme, eruptive variables like UV Ceti flare stars and FU Orionis objects undergo sudden, dramatic outbursts linked to magnetic reconnection events or disk accretion instabilities.
+
+Among the most scientifically important classes are the pulsating variables used as standard candles: classical Cepheids (DCEP), whose period-luminosity relation underpins the extragalactic distance ladder, and RR Lyrae stars (RR), horizontal-branch pulsators that trace the old stellar populations of the Galactic halo and globular clusters.
+
+Because the GCVS draws on over a century of photometric monitoring, it captures variability on timescales inaccessible to modern surveys that have operated for only a few years. Many entries include epochs of maximum light stretching back to the early twentieth century, enabling studies of period changes, evolutionary effects, and long-term amplitude modulation that would be impossible from any single contemporary survey alone.
+
+
+This dataset is suitable for **tabular classification** tasks.
 
 ## Schema
 
-| Column | Type | Description |
-|--------|------|-------------|
-| `gcvs_name` | string | GCVS designation (e.g. "R And", "delta Cep") |
-| `ra_deg` | float64 | Right ascension J2000 (degrees) |
-| `dec_deg` | float64 | Declination J2000 (degrees) |
-| `variable_type` | string | Variability type (e.g. M, SR, EA, DCEP, RR) |
-| `magnitude_max` | float64 | Maximum brightness (mag, lower = brighter) |
-| `magnitude_min_flag` | string | Flag on minimum magnitude (e.g. "(" for amplitude) |
-| `magnitude_min` | float64 | Minimum brightness (mag) |
-| `period_days` | float64 | Period in days |
-| `epoch_jd` | float64 | Epoch of maximum/minimum (Julian Date) |
-| `spectral_type` | string | Spectral type |
+| Column | Type | Description | Sample | Null % |
+|--------|------|-------------|--------|--------|
+| `gcvs_name` | str | GCVS official designation — Greek letter + constellation for bright variables (e.g. 'R And', 'delta Cep'), or V+number for fainter ones (e.g. 'V1500 Cyg'); IAU-recognized identifier | AA And | 0.0% |
+| `ra_deg` | float64 | Right ascension, ICRS J2000.0, in decimal degrees (0-360) | 346.3451666666666 | 0.3% |
+| `dec_deg` | float64 | Declination, ICRS J2000.0, in decimal degrees (-90 to +90) | 47.67630555555555 | 0.3% |
+| `variable_type` | str | GCVS variability type code; common values: DCEP (classical Cepheid, period-luminosity standard candle), RR (RR Lyrae, old metal-poor horizontal-branch pulsator), M (Mira, AGB long-period pulsator), SR (semi-regular), EA/EB/EW (eclipsing binaries), UV (UV Ceti/flare star), N (nova), SN (supernova); ~100 distinct types | EB | 1.4% |
+| `magnitude_max` | float64 | Brightness at maximum light in V-band (mag); lower value = brighter star; null for a small number of entries | 10.3 | 0.4% |
+| `magnitude_min_flag` | str | Qualifier on magnitude_min: '(' means value is amplitude (mag range) rather than absolute minimum magnitude; blank otherwise | < | 83.4% |
+| `magnitude_min` | float64 | Brightness at minimum light in V-band (mag); for eclipsing binaries this is the primary minimum; amplitude = magnitude_min - magnitude_max; null for irregular variables with poorly defined minima | 11.2 | 0.8% |
+| `period_days` | float64 | Pulsation or orbital period in days; null for irregular variables (type L, I), single-event novae, and eruptive stars with no recurring period | 0.9350969 | 34.2% |
+| `epoch_jd` | float64 | Julian Date of the light curve reference point — epoch of maximum light for pulsators, epoch of primary minimum for eclipsing binaries; null when no reliable epoch has been established | 52500.73 | 46.1% |
+| `spectral_type` | str | MK spectral type at the phase of maximum light; null for ~40% of entries where spectral classification is unavailable | B8V | 75.2% |
 
 ## Quick stats
 
@@ -99,6 +79,13 @@ that would be impossible from any single contemporary survey alone.
 ```python
 from datasets import load_dataset
 
+ds = load_dataset("juliensimon/gcvs-variable-stars", split="train")
+df = ds.to_pandas()
+```
+
+```python
+from datasets import load_dataset
+
 ds = load_dataset("juliensimon/gcvs-variable-stars", split="train")
 df = ds.to_pandas()
 
@@ -120,42 +107,36 @@ plt.gca().invert_yaxis()
 plt.xlabel("Period (days)")
 plt.ylabel("Magnitude (max brightness)")
 plt.title("GCVS Period vs Magnitude")
+plt.show()
 ```
 
 ## Data source
 
-[General Catalogue of Variable Stars](https://www.sai.msu.su/gcvs/gcvs/)
-(Samus' N.N., Kazarovets E.V., Durlevich O.V., Kireeva N.N., Pastukhova E.N., 2017,
-Astronomy Reports, 61, 80), accessed via [VizieR](https://vizier.cds.unistra.fr/), CDS Strasbourg.
-
-## Update schedule
-
-Quarterly (1st of the month at 08:00 UTC) via [GitHub Actions](https://github.com/juliensimon/space-datasets).
+https://www.sai.msu.su/gcvs/gcvs/
 
 ## Related datasets
 
-- [pulsar-catalog](https://huggingface.co/datasets/juliensimon/pulsar-catalog) -- ATNF Pulsar Catalogue
-- [messier-catalog](https://huggingface.co/datasets/juliensimon/messier-catalog) -- Messier deep-sky objects
-- [ngc-ic-catalog](https://huggingface.co/datasets/juliensimon/ngc-ic-catalog) -- NGC/IC deep-sky catalog
+- [juliensimon/pulsar-catalog](https://huggingface.co/datasets/juliensimon/pulsar-catalog)
+
+- [juliensimon/messier-catalog](https://huggingface.co/datasets/juliensimon/messier-catalog)
 
-## Pipeline
+- [juliensimon/ngc-ic-catalog](https://huggingface.co/datasets/juliensimon/ngc-ic-catalog)
 
-Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)
+> If you find this dataset useful, please consider [giving it a like](https://huggingface.co/datasets/juliensimon/gcvs-variable-stars) on Hugging Face. It helps others discover it.
 
-## Support
+## About the author
 
-If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/gcvs-variable-stars) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.
+Created by [Julien Simon](https://julien.org) — AI Operating Partner at Fortino Capital. Part of the [Space Datasets](https://julien.org/datasets) collection.
 
 ## Citation
 
 ```bibtex
 @dataset{gcvs_variable_stars,
-  author = {Simon, Julien},
   title = {General Catalogue of Variable Stars (GCVS)},
+  author = {juliensimon},
   year = {2026},
-  publisher = {Hugging Face},
   url = {https://huggingface.co/datasets/juliensimon/gcvs-variable-stars},
-  note = {Based on GCVS (Samus' et al. 2017) via VizieR CDS Strasbourg}
+  publisher = {Hugging Face}
 }
 ```
 

data/gcvs_variable_stars.parquet

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