TIC 59388389
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 1.1856-day period, a 0.89% primary eclipse, a 0.99% secondary eclipse at phase 0.549. Automated cross-checks question this period - see below.
TIC 59388389 is a candidate eclipsing binary star system identified through automated analysis of TESS photometry. The system shows a primary eclipse with a depth of 0.53% occurring every 1.1856 days, detected with a signal-to-noise ratio of 65.7 using the Box Least Squares algorithm. Pixel-level analysis via difference imaging confirms the signal originates near the target location, with a peak signal-to-noise of 28.3 and a centroid offset of 0.7 arcsec. No secondary eclipse was detected in the available data. The candidate does not appear in six major variable-star catalogs, making it a previously uncatalogued object. While the machine learning screening score of 0.44 indicates moderate confidence that this represents a real stellar target, continued observation would help establish the nature and properties of this system.
- Surface brightness ratio
- 1.11
- Companion temperature
- ~13,448 K
- Companion / star radius
- ~0.09
- Face hidden at primary eclipse
- ~1%
- Separation
- ~1.8 x the star's radius
- Eccentricity
- at least 0.077
- Secondary eclipse phase
- 0.549 measured, 0.549 in this orbit
Zoomed: both stars drawn about 0x larger than their real size relative to the orbit, so they overlap for longer than the real eclipse lasts. A star's surface never gets dimmer during an eclipse - part of it is simply hidden. What drops is the total light we receive, shown exactly by the readout and bar below from the real light curve; the glow dims with it, exaggerated so small dips show. Colours follow temperature on a stellar colour scale, saturated so the differences show; the star's is its catalogue value (12,720 K). The companion's colour, sizes and orbit shape are estimates from the eclipse depths, duration and timing, assuming central eclipses and spherical stars - good to perhaps tens of percent. Only the relative orbit is shown; both stars really circle their common centre of mass. Animated about 4,268x faster than real on average, slowing down through each eclipse, and starting from where the system is in its orbit right now. Hover to pause.
- Secondary2026-10-19 06:37 UTC
- Primary2026-10-19 19:27 UTC
- Secondary2026-10-20 11:04 UTC
Computed from the fitted ephemeris. Approximate - not corrected for your location or for light-travel time across Earth's orbit.
The signal
A repeating, consistent dip in brightness.
Residual scatter 1.166% (observed minus binned median).
Automated cross-checks question this period - see Caveats below.
- Period
- 1.18563 d
- Primary depth
- 0.89%
- Secondary depth
- 0.99%
- Epoch (T0)
- 2420.897 BTJD
- Duration
- 5.86 h
The catalog check
Cross-matched against known variable-star catalogs to rule out anything already listed.
- VSXNot found
- ASAS-SNNot found
- Gaia eclipsing-binary tableNot found
- Gaia variable classificationNot found
- TESS EB catalog (Prsa+2022)Not found
- ExoFOP TOI listNot found
0/6 catalogs list a known variable at this position.
No known variable star or catalogued match at this position.
- Catalogs checked
- 6
- Matches
- 0
The pixel check
Confirms the dimming is on the target star, not a nearby source.
Out/in share one sqrt colour scale; in-eclipse = out-of-eclipse minus difference. TESS sector 74.
- 28.3
- 0.03 px1"
- 0.0325 phase
- TIC 593883720.43 px, dT 4.2
- 0.88
- 74
The dimming is centred on the target star. No nearby contaminant detected.
- Centroid offset
- 0.03 px
- Difference SNR
- 28.3
- Capable neighbour
- TIC 59388372
- TESS sector
- 74
The Gaia view
A second spacecraft's measurements: how far away the star is, how bright and what colour, and whether its position fits a single star.
The latest Gaia context file does not include this candidate yet, so there is no Gaia view to show.
The ground-survey check
An independent instrument, different years: does real ZTF photometry show the eclipse at the period TESS measured?
The latest ground-survey file does not include this candidate yet, so there is no independent ZTF check to show.
Fold it yourself
Adjust the period and watch the eclipse appear.
Shown at the true period. The raw light curve needed to re-fold at other periods has not been exported yet - this slider unlocks automatically once it is.
The period the pipeline measured. Drag the slider away from it and the eclipse smears out.
- True period
- 1.18563 d
- BLS period
- 1.18563 d
- Odd/even z
- 1.52
Caveats
Known limitations and things to check.
Cross-check:No eclipse at 46 of 134 covered epochs where the 1.18563 d period predicts one (each under half the typical depth, > 5 sigma below it). The period is probably wrong - the dips seen may be separate eclipses of a longer-period system.
VIIIInstrument
Raw values, fits and technical details.
Instrument
Raw values, fits and technical details.
Full statistics
- 1.18563 d
- 1.18563 dsame
- 0.89% +/- 0.08%seen 24/134
- ML screening score
- 0.442logistic_regression
- 0.99% +/- 0.01%phase 0.549, 92 sigma
- 1.52< 3
- 0.5929 dpower 0.15
- 5.9 h
- Distance (TIC, Gaia-based)
- 3065 pc+/- 283
- 11.94 / 11.66
- 12720 K / -
- RA / Dec (J2000)
- 19h 48m 54.6s +30d 40m 20s
- 65.7 / 28.3
- 44,955 ptsover 1113 d
Eclipse close-ups
Same flux scale on both panels. Line: binned median. Shown in place of an orbit animation - this pipeline measures eclipses, it does not fit an orbit.
Period alias analysis
Odd/even depth z = 1.52 (gate 3.0): alternate eclipses match, so the BLS period stands.
O - C timing
24 eclipses timed, rms 68.04 min, reduced chi-square 576.36 (22 dof): more scatter than the timing errors explain - worth a closer look.
Each eclipse timed by fitting the star's own mean eclipse profile; fitted P = 1.185726 +/- 0.000002 d.