Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits
Data files
Feb 25, 2025 version files 976.75 KB
-
data_behind_Fig2.zip
373.43 KB
-
pydia_OB160007.tar
376.32 KB
-
README.md
8.83 KB
-
sensitivity.tar
198.14 KB
-
table_S3.xlsx
20.03 KB
Abstract
Exoplanets classified as super-Earths are commonly observed on short period orbits, close to their host stars, but their abundance on wider orbits is poorly constrained. Gravitational microlensing is sensitive to exoplanets on wide orbits. We observed the microlensing event OGLE-2016-BLG-0007, which indicates an exoplanet with a planet-to-star mass ratio roughly double the Earth- Sun mass-ratio, on an orbit longer than Saturn’s. We combine this event with a larger sample from a microlensing survey to determine the distribution of mass ratios for planets on wide orbits. We infer there are ~0.35 super-Earth planets per star on Jupiter-like orbits. The observations are most consistent with a bimodal distribution, with separate peaks for super-Earths and Jupiters. We suggest this reflects differences their formation processes.
https://doi.org/10.5061/dryad.ksn02v7cg
Data, tabulated sensitivities, and codes from the paper.
Description of the data and file structure
data_behind_Fig2.zip
These are the light curve files showing the data used in Figure 2. Dates are in Heliocentric Julian Date (HJD) or HJD - 2450000.
In the tables below, ADU = Analog Digital Units
KMTNet I-band data:
KMTA02_I.pysis.dat
KMTA42_I.pysis.dat
KMTC02_I.pysis.dat
KMTC42_I.pysis.dat
KMTS02_I.pysis.dat
KMTS42_I.pysis.dat
Filename convention: KMT[Site][Field]_I.pysis.dat
Columns: HJD - 2450000, magnitude, mag_error, flux, flux_error, FWHM, Sky
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| HJD - 2450000 | Heliocentric Julian Date (HJD) - 2450000 | days |
| magnitude | magnitude | mag |
| mag_error | The uncertainty in the magnitude | mag |
| flux | flux | ADU |
| flux_error | The uncertainty in the flux | ADU |
| FWHM | Full-Width-Half-Maximum of the point spread function | pixels |
| Sky | Sky background | ADU |
MOA data:
MB16088.dat
Points that deviate from the model by >3 sigma have been removed.
Columns: HJD, Flux, Flux err, FWHM, Sky, Airmass
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| HJD | Heliocentric Julian Date (HJD) | days |
| Flux | flux | ADU |
| Flux err | The uncertainty in the flux | ADU |
| FWHM | Full-Width-Half-Maximum of the point spread function | arcsec |
| Sky | Sky background | ADU |
| Airmass | airmass | n/a |
OGLE data:
OGLE-2016-BLG-0007.dat
Points that deviate from the model by >3 sigma have been removed.
Columns: HJD, magnitude, mag error
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| HJD | Heliocentric Julian Date (HJD) | days |
| magnitude | magnitude | mag |
| mag_error | The uncertainty in the magnitude | mag |
pydia_OB160007.tar
Files used for measuring the source color from KMTNet observations.
KMTC02-source_position.pydia:
X, Y pixel coordinates of the source.
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| X | X position on the detector | pixels |
| Y | Y position on the detector | pixels |
KMTC02I.out-KMTC02V.out-CMDdata:
V- and I-band data of stars in the field for constructing a color-magnitude diagram (CMD).
Columns are as indicated at the top of the file.
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| ID | ID number | n/a |
| xpos | X position | pixels |
| ypos | Y position | pixels |
| V | V-band magnitude | mag |
| V_err | uncertainty in V-band magnitude | mag |
| I | I-band magnitude | mag |
| I_err | uncertainty in I-band magnitude | mag |
KMTC02I-lightcurve.pydia
KMTC02V-lightcurve.pydia
I- and V-band light curve data, respectively, in the same flux scale as the CMD.
Columns are as indicated at the top of the files.
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| Date | Heliocentric Julian Date (HJD) - 2450000 | days |
| Delta_Flux | difference flux | ADU |
| Err_Delta_Flux | uncertainty in difference flux | ADU |
| Mag | magnitude | mag |
| Err_Mag | uncertainty in magnitude | mag |
| Q | Image quality metric | n/a |
| FWHM | Full-Width-Half-Maximum of the point spread function | arcsec |
| Roundness | roundness of point spread function | n/a |
| Sky | Sky background | ADU |
| Signal | Mean counts above Sky per pixel | ADU |
The magnitude values (Mag) are calculated from the Delta_Flux values by adding
a constant offset. If the resulting flux value is <0, this results in a nan
value for the Mag and Err_Mag. If Err_Delta_Flux > Delta_Flux, Err_Mag will
also be nan.
sensitivity.tar
Calculated sensitivities of the KMTNet survey for the 2018 and 2019 seasons.
Tabular data giving the calculated sensitivities of the 2018 and 2019 KMTNet seasons. May be used to reproduce Figure S1 in the manuscript or combined with the planet detections in Table S3 to reproduce Figure 3.
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| log q | Logarithm of the planet-star mass ratio | n/a |
| log s | Logarithm of the projected planet-star separation scaled to the Einstein radius | n/a |
| N | expected number of detections if all events had a planet of this type | n/a |
| eff | fraction of planets of this type that are detectable | n/a |
flogq_comb_2018.res
Sensitivity as a function of log q calculated for the 2018 KMTNet season.
Columns: log q, N, eff
flogq_comb_2019.res
Sensitivity as a function of log q calculated for the 2019 KMTNet season.
Columns: log q, N, eff
flogq_comb_all.res
Combined sensitivity as a function of log q for the 2018 and 2019 KMTNet seasons.
Columns: log q, N, eff
2D_sensitivity_all.res
Combined 2D sensitivity as a function of log q and log s for the 2018 and 2019 KMTNet seasons corresponding to panel A in Figure S1 of the manuscript.
Columns: log s, log q, N
table_S3.xlsx
Machine-readable version of Table S3.
Columns: Event Name, KMTNet Name, log(q), err(log(q)), s, error(s), Reference
| VARIABLE | DEFINITION | UNITS |
|---|---|---|
| Event Name | primary designation for each event based on which survey identified the event first | n/a |
| KMTNet Name | designation assigned by the KMTNet Collaboration | n/a |
| log(q) | Logarithm of the planet-star mass ratio | n/a |
| err(log(q)) | uncertainty in log(q) | n/a |
| s | projected planet-star separation scaled to the Einstein radius | n/a |
| error(s) | uncertainty in s | n/a |
| Reference | Link to journal paper | n/a |
Both the Event Names and KMTNet Name are presented in abbreviated format: SBYYNNNN, where S is the survey that identified the event (O = OGLE, and K = KMT), B indicates that the event was identified in the Galactic Bulge fields observed by that survey, YY is the 2-digit abbreviation for the year (e.g. 16 = 2016), and NNNN is the 4-digit number assigned to the event by the survey in the order that the events were identified within a year.
code_WZ.zip
Codes for reproducing the analysis.
AnomalyFinder/
- downhill.py: code for PSPL fitting
- gen_res.py: code for generating the residuals
- small_peak.py: code for the anomaly search
FAP_analysis/
- draw.py: code for generating the KMT sensitivity curve
- gen_sample.py: code for generating 63-planet samples
- fit.py: code for fitting 63-planet samples
frequency_analysis/
- mf.py: code for frequency analysis
- flogq_comb_use.res: KMTNet sensitivity for different mass-ratio
- sample_logq_sens.txt: mass-ratio and the corresponding sensitivity for planets in the sample
- Zang, Weicheng; Jung, Youn Kil; Yee, Jennifer et al. (2025). Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits. Zenodo. https://doi.org/10.5281/zenodo.14852776
- Zang, Weicheng; Jung, Youn Kil; Yee, Jennifer et al. (2025). Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits. Zenodo. https://doi.org/10.5281/zenodo.14852775
- Sangtarash, Parisa; Yee, Jennifer C. (2025). Investigating the Binary Source Degeneracy for Wide-orbit Planets. The Astronomical Journal. https://doi.org/10.3847/1538-3881/adeb76
- Zang, Weicheng; Jung, Youn Kil; Yee, Jennifer C. et al. (2025). Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits. Science. https://doi.org/10.1126/science.adn6088