TIC 437022904
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 1.4310-day period (twice the BLS period), a 0.52% primary eclipse, a 0.56% secondary eclipse at phase 0.455. Automated cross-checks question this period - see below.
TIC 437022904 is a candidate eclipsing binary star with an orbital period of 1.431008 days, detected through automated analysis of TESS photometry. The primary eclipse produces a dimming of 0.49%, while no secondary eclipse was detected. The eclipse signal achieves a detection significance of 573.0 in the Box-Least-Squares search, and pixel-level analysis confirms a peak signal-to-noise of 9.0, though the centroid offset of 2.9 arcsec from the target position warrants attention. The candidate does not appear in six major variable-star catalogs, making it a previously unlisted object. However, data quality checks reveal that alternating eclipses differ significantly in depth, suggesting the true orbital period is double the initial BLS detection - a pattern that affects interpretation of the eclipse properties but does not change the pixel-level confirmation or eclipse timing measurements.
- Surface brightness ratio
- 1.08
- Companion temperature
- ~7,256 K
- Companion / star radius
- ~0.08
- Face hidden at primary eclipse
- ~1%
- Separation
- ~2.1 x the star's radius
- Eccentricity
- at least 0.071
- Secondary eclipse phase
- 0.455 measured, 0.455 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 (7,046 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 5,152x 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 06:54 UTC
- Primary2026-10-20 01:38 UTC
- Secondary2026-10-20 17:15 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 0.396% (observed minus binned median).
Automated cross-checks question this period - see Caveats below.
- Period
- 1.43101 d
- Primary depth
- 0.52%
- Secondary depth
- 0.56%
- Epoch (T0)
- 3235.985 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 71.
- 9.0
- 0.14 px3"
- -0.0475 phase
- TIC 4370229142.21 px, dT 5.7
- 0.83
- 71
The dimming is centred on the target star. No nearby contaminant detected.
- Centroid offset
- 0.14 px
- Difference SNR
- 9.0
- Capable neighbour
- TIC 437022914
- TESS sector
- 71
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?
No ZTF observations at this position (declination 20.7 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
- 1.43101 d
- BLS period
- 0.71550 d
- Odd/even z
- 7.00
Caveats
Known limitations and things to check.
Cross-check:No eclipse at 13 of 33 covered epochs where the 1.43101 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.
- Period alias:Odd/even eclipse-depth z-score is 7.00 (gate > 3.0): alternating eclipses differ significantly in depth, the signature of a true period double what BLS found. Pixel-check confirmation and eclipse timing are unaffected - report the corrected period, 1.431008 d, in any write-up.
VIIIInstrument
Raw values, fits and technical details.
Instrument
Raw values, fits and technical details.
Full statistics
- 1.43101 d
- 0.71550 dalias
- 0.52% +/- 0.04%seen 20/33
- ML screening score
- 0.626logistic_regression
- 0.56% +/- 0.01%phase 0.455, 65 sigma
- 7.00> 3: alias
- 0.7175 dpower 0.38
- 5.9 h
- Distance (TIC, Gaia-based)
- 233 pc
- 9.62 / 9.35
- 7046 K / 1.71 Rsun
- RA / Dec (J2000)
- 07h 07m 21.9s +20d 43m 19s
- 573.0 / 9.0
- 19,177 ptsover 826 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 = 7.00 (gate 3.0): alternate eclipses differ, so the true period is 2 x 0.7155 = 1.4310 d.
O - C timing
18 eclipses timed, rms 56.15 min, reduced chi-square 1196.73 (16 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 = 1.431132 +/- 0.000004 d.