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juliensimon/asteroid-lightcurves-lcdb

Asteroid Lightcurve Database (LCDB) Credit: NASA/ESA Part of a dataset collection on Hugging Face. Dataset description The Asteroid Lightcurve Database (LCDB) is the most comprehensive compilation of asteroid rotation parameters, maintained by Brian Warner at MinorPlanet.info. For each asteroid it provides the best-estimate rotation period (hours), lightcurve amplitude range (magnitudes), a reliability quality code (U rating 1–3), taxonomic classification… See the full description on the dataset page: https://huggingface.co/datasets/juliensimon/asteroid-lightcurves-lcdb.

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Dataset Card

Asteroid Lightcurve Database (LCDB)

<div align="center"> <img src="banner.jpg" alt="Rosetta spacecraft approaching Comet 67P/Churyumov-Gerasimenko" width="400"> <p><em>Credit: NASA/ESA</em></p> </div>

Part of a [dataset collection](https://huggingface.co/collections/juliensimon/orbital-mechanics-datasets-69c24caca4ab3934c9856994) on Hugging Face.

Dataset description

The Asteroid Lightcurve Database (LCDB) is the most comprehensive compilation of asteroid rotation parameters, maintained by Brian Warner at MinorPlanet.info. For each asteroid it provides the best-estimate rotation period (hours), lightcurve amplitude range (magnitudes), a reliability quality code (U rating 1–3), taxonomic classification, diameter, albedo, and photometric slope parameters.

Asteroid rotation is a direct probe of internal structure, collisional history, and non-gravitational physics. The distribution of spin rates reveals a sharp "spin barrier" near 2.2 hours for objects larger than about 200 meters: virtually no large asteroids rotate faster than this critical period, because centrifugal force would exceed the gravitational self-binding force of a rubble-pile body. The handful of super-fast rotators below this barrier are either monolithic rocks or very small objects where cohesive forces provide sufficient strength. This spin barrier is one of the strongest pieces of evidence that most asteroids larger than a few hundred meters are gravitationally bound rubble piles.

Lightcurve amplitude encodes shape information. A spherical object shows no brightness variation; an elongated body produces deep dips twice per rotation as its cross-section varies. Amplitudes above 1.0 magnitude imply axis ratios of at least 2.5:1, suggesting highly elongated or contact-binary morphologies. The binary_type column flags known binary and multiple systems, which comprise roughly 15% of near-Earth asteroids and play a key role in understanding the YORP spin-up mechanism.

The taxonomic classifications and albedo values enable population-level studies linking surface composition to rotational properties. Low-albedo C-complex asteroids tend to have longer rotation periods on average than high-albedo S-complex asteroids of the same size, reflecting differences in bulk density, internal structure, or collisional evolution timescales. These correlations constrain models of how the asteroid belt was assembled and dynamically processed over 4.6 billion years of solar system history.

Schema

ColumnTypeDescriptionSampleNull %
numberInt64IAU catalog number (positive integer); null for unnumbered asteroids with only a provisional designation15.4%
namestringIAU proper name (e.g., 'Ceres', 'Eros'); null for unnamed objectsCeres0.0%
designationstringMPC provisional designation (e.g., '2024 YR4'); null for numbered objects without a recorded provisional designationA910 CB1.2%
familyInt64Dynamical family membership code from the LCDB family list; null if the asteroid is not assigned to a known collisional family91060.0%
taxonomystringSpectral taxonomic class (Tholen or Bus-DeMeo system, e.g., S, C, V, Sq); null for asteroids without a published classificationC0.1%
diameter_kmfloat64Estimated effective diameter in km; null for asteroids without a published size estimate; sources vary (IRAS, WISE, radar, occultation)939.40.1%
abs_magnitude_hfloat64Absolute magnitude H (magnitude at 1 AU, zero phase angle); null for a small fraction of entries3.530.1%
g_paramfloat64IAU HG photometric slope parameter G; typical range 0.0–0.5; null if not published0.1219.5%
g1_paramfloat64HG1G2 phase function parameter G1; alternative to G for non-standard phase curves; null if not published0.9881.6%
g2_paramfloat64HG1G2 phase function parameter G2; used together with G1; null if not published0.38100.0%
albedofloat64Geometric albedo (fraction of incident light reflected, 0–1); typical C-type 0.03–0.10, S-type 0.15–0.35; null if not published0.07750.0%
period_hfloat64Best-estimate rotation period in hours; range ~0.0003 h (super-fast rotators) to >1000 h for slow rotators; null if no period has been determined9.074174.1%
period_flagstringQualifier for the period value: > = lower limit only, < = upper limit, S = synodic period, D = double-peaked, U = uncertain; null if no flagS90.5%
period_descriptionstringFree-text notes on the period determination (e.g., method, caveats); null if noneng100.0%
amplitude_minfloat64Minimum observed lightcurve amplitude in magnitudes; lower bound across all available apparitions; null if undetermined0.0380.7%
amplitude_maxfloat64Maximum observed lightcurve amplitude in magnitudes; >0.9 mag implies axis ratio ≥2.5:1; null if undetermined0.0610.2%
quality_code_uobjectLightcurve quality rating U: 1 = tentative/very uncertain, 2 = fair (may be refined), 3 = reliable/unambiguous; suffixes + and - indicate borderline ratings39.3%
notesstringMiscellaneous flags and comments from the LCDB; null if none386.7%
binary_typestringBinary or multiple system designation: B = confirmed binary, M = confirmed multiple, ? = suspected; null if no binary evidenceB98.5%

Quick stats

  • 36,259 asteroids
  • 34,755 with measured rotation periods (median 7.32 h)
  • 5,859 with high-quality periods (U = 3 or 3-)
  • 36,233 with known diameters
  • 36,250 with measured albedos
  • 558 binary/multiple systems
  • 114 distinct taxonomic classes
  • Fastest rotator: 2020 HS7 at 0.00083 hours

Usage

python
from datasets import load_dataset
import matplotlib.pyplot as plt

ds = load_dataset("juliensimon/asteroid-lightcurves-lcdb", split="train")
df = ds.to_pandas()

# Well-established rotation periods only (U >= 3)
reliable = df[df["quality_code_u"].isin(["3", "3-"])]

# Fast rotators (period < 2.2 h = spin barrier)
fast = df[(df["period_h"] < 2.2) & (df["quality_code_u"].isin(["3", "3-", "2+", "2"]))]

# S-type asteroids with known diameters and periods
s_type = df[
    (df["taxonomy"].str.startswith("S", na=False))
    & (df["diameter_km"].notna())
    & (df["period_h"].notna())
]

# Period vs diameter scatter — visualize the spin barrier
sub = df[(df["period_h"].notna()) & (df["diameter_km"].notna()) & (df["diameter_km"] > 0)]
plt.figure(figsize=(10, 7))
plt.scatter(sub["diameter_km"], sub["period_h"], s=1, alpha=0.3, color="steelblue")
plt.axhline(2.2, color="red", linestyle="--", linewidth=1.2, label="Spin barrier (2.2 h)")
plt.xscale("log")
plt.yscale("log")
plt.xlabel("Diameter (km)")
plt.ylabel("Period (hours)")
plt.title("Asteroid Spin Rate vs Size — LCDB")
plt.legend()
plt.tight_layout()
plt.show()

Data source

https://minplanobs.org/mpinfo/php/lcdb.php

Related datasets

Citation

bibtex
@dataset{asteroid_lightcurves_lcdb,
  title = {Asteroid Lightcurve Database (LCDB)},
  author = {Simon, Julien},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/asteroid-lightcurves-lcdb},
  publisher = {Hugging Face},
  note = {Derived from IAU Minor Planet Center, https://minplanobs.org/mpinfo/php/lcdb.php}
}

License

CC-BY-4.0