TIC 216935767
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 0.9859-day period, a 3.86% primary eclipse, no significant secondary eclipse. Automated cross-checks question this period - see below.
TIC 216935767 is a candidate eclipsing binary star identified through automated analysis of TESS photometry. The system shows a primary eclipse with a depth of 3.00 percent and an orbital period of 0.9859 days, detected with a signal-to-noise ratio of 281.9 using the Box Least Squares algorithm. Pixel-level image analysis confirms the signal at the target location with a peak signal-to-noise of 27.3, though a centroid offset of 1.4 arcsec was measured. No secondary eclipse was detected in the data. The candidate does not appear in any of six major variable-star catalogs, making it a potentially new object. The pipeline's machine learning model assigned this target a screening score of 0.30, and the light curve passed all automated data quality checks.
- Surface brightness ratio
- companion faint - no secondary eclipse
- Companion temperature
- below ~3,125 K
- Companion / star radius
- ~0.20
- Face hidden at primary eclipse
- ~4%
- Separation
- ~3.2 x the star's radius
- Eccentricity
- consistent with circular
Zoomed: both stars drawn about 1x 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 (4,962 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 3,549x 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.
- Primary2026-10-19 08:45 UTC
- Secondary2026-10-19 20:35 UTC
- Primary2026-10-20 08:25 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 2293618630100301.500% (observed minus binned median).
Automated cross-checks question this period - see Caveats below.
- Period
- 0.98593 d
- Primary depth
- 3.86%
- Epoch (T0)
- 1625.500 BTJD
- Duration
- 2.88 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 12.
- 27.3
- 0.07 px1"
- 0.0150 phase
- TIC 2169357800.21 px, dT -1.4
- 0.97
- 12
The dimming is centred on the target star. No nearby contaminant detected.
- Centroid offset
- 0.07 px
- Difference SNR
- 27.3
- Capable neighbour
- TIC 216935780
- TESS sector
- 12
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.
Its colour is redder than the Sun's, which usually means cooler - though dust along the way also reddens light.
Not plotted on the diagram: its distance is not measured well enough to place it.
Gaia note: parallax SNR too low (2.8) - noisy astrometric solution, distance unreliable
Source: ESA Gaia DR3, source 5951220794037952896.
Gaia's position measurements fit this source poorly (RUWE 1.83, above the usual 1.4). That often means more than one star is there - most likely a wider third star or an unresolved neighbour, since a tight eclipsing pair barely moves Gaia's image. Context, not confirmation.
- Distance
- not reliable
- Apparent G
- 15.70
- Colour BP-RP
- 1.80
- RUWE
- 1.83
- Match offset
- 0.18 arcsec
The ground-survey check
An independent instrument, different years: does real ZTF photometry show the eclipse at the period TESS measured?
No ZTF observations at this position (declination -45.9 deg) - likely too far south for ZTF's footprint, which covers the sky north of roughly -31 deg. Not a mark against the candidate, just a gap in ground-survey coverage.
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
- 0.98593 d
- BLS period
- 0.98593 d
- Odd/even z
- 1.10
Caveats
Known limitations and things to check.
Cross-check:No eclipse at 1 of 18 covered epochs where the 0.98593 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
- 0.98593 d
- 0.98593 dsame
- 3.86% +/- 0.11%seen 16/18
- ML screening score
- 0.303logistic_regression
- < 0.43%none at 5 sigma
- 1.10< 3
- 1.2510 dpower 0.01
- 2.9 h
- Distance (TIC, Gaia-based)
- 3572 pc+/- 1354
- 15.71 / 14.79
- 4962 K / 6.09 Rsun
- RA / Dec (J2000)
- 17h 18m 5.8s -45d 56m 13s
- 281.9 / 27.3
- 1,049 ptsover 28 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 = 1.10 (gate 3.0): alternate eclipses match, so the BLS period stands.
O - C timing
15 eclipses timed, rms 59.41 min, reduced chi-square 1931.24 (13 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 = 0.983936 +/- 0.000026 d.