TIC 445266372
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 11.6125-day period (twice the BLS period), a 16.87% primary eclipse, a 1.60% secondary eclipse at phase 0.196.
TIC 445266372 is a candidate eclipsing binary star with an orbital period of 11.61 days, detected through automated analysis of TESS photometry and pixel-level imaging. The primary eclipse produces an 8.84% dimming, while a secondary eclipse was detected at 6.7 sigma significance. The binary signal achieved a detection significance of 106.4 on the Box Least Squares periodogram, with pixel-level confirmation showing a peak signal-to-noise ratio of 42.3 and a centroid offset of 1.6 arcsec from the target. The object does not appear in six major variable-star catalogs, making it a novel candidate. However, analysis reveals that alternating eclipses differ significantly in depth, suggesting the true period is double the initially detected value - a pattern consistent with a real eclipsing system rather than instrumental artifacts. Pixel-level confirmation and eclipse timing remain unaffected by this period correction.
- Surface brightness ratio
- 0.09
- Companion temperature
- ~3,485 K
- Companion / star radius
- ~0.41
- Face hidden at primary eclipse
- ~17%
- Separation
- ~44 x the star's radius
- Eccentricity
- at least 0.477
- Secondary eclipse phase
- 0.196 measured, 0.208 in this orbit
Zoomed: both stars drawn about 13x 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 (6,215 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 41,805x 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.
- Primary2026-10-24 00:53 UTC
- Secondary2026-10-26 07:36 UTC
- Primary2026-11-04 15:35 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 17.464% (observed minus binned median).
Alternate eclipses differ in depth, so the true period is twice the search period.
- Period
- 11.61254 d
- Primary depth
- 16.87%
- Secondary depth
- 1.60%
- Epoch (T0)
- 1469.240 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 6.
- 42.3
- 0.07 px2"
- 0.0000 phase
- TIC 4452676941.20 px, dT 2.0
- 0.95
- 6
The dimming is centred on the target star. No nearby contaminant detected.
- Centroid offset
- 0.07 px
- Difference SNR
- 42.3
- Capable neighbour
- TIC 445267694
- TESS sector
- 6
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.
It is about 5,108 light years away: the light TESS recorded left it around 5,108 years ago.
Together the two stars give off about 2.6 times the Sun's light in Gaia's band - before correcting for interstellar dust, which only makes distant stars look fainter.
Its colour is redder than the Sun's, which usually means cooler - though dust along the way also reddens light.
Source: ESA Gaia DR3, source 2947391521286533376.
Gaia's measurements fit a single point of light well (RUWE 0.98), as expected for a pair too close for Gaia to separate.
- Distance
- 1,566 +/- 51 pc
- Light-travel time
- ~5,108 years
- Apparent G
- 14.63
- Absolute G
- 3.65
- Colour BP-RP
- 1.04
- RUWE
- 0.98
- Match offset
- 0.13 arcsec
The ground-survey check
An independent instrument, different years: does real ZTF photometry show the eclipse at the period TESS measured?
- ZTF g (113 pts, 1 outlier)Too few outliers to test
- ZTF r (146 pts, 1 outlier)Too few outliers to test
Folded at the TESS-measured period of 5.80627 d, no band shows a phase cluster tight enough to rule out chance. Ground-survey cadence is sparse - a handful of epochs per orbit - so this is the expected outcome for most real eclipses, not evidence against this one.
Source: ZTF public light-curve archive (IRSA), independent of the TESS data used to detect this candidate.
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
- 11.61254 d
- BLS period
- 5.80627 d
- Odd/even z
- 3.62
Caveats
Known limitations and things to check.
- Period alias:Odd/even eclipse-depth z-score is 3.62 (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, 11.612539 d, in any write-up.
VIIIInstrument
Raw values, fits and technical details.
Instrument
Raw values, fits and technical details.
Full statistics
- 11.61254 d
- 5.80627 dalias
- 16.87% +/- 0.16%seen 2/2
- ML screening score
- 0.533logistic_regression
- 1.60% +/- 0.30%phase 0.196, 5 sigma
- 3.62> 3: alias
- 6.3971 dpower 0.03
- 2.9 h
- Distance (TIC, Gaia-based)
- 1582 pc+/- 79
- 14.65 / 14.11
- 6215 K / 1.93 Rsun
- RA / Dec (J2000)
- 06h 43m 26.1s -15d 31m 49s
- 106.4 / 42.3
- 903 ptsover 22 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 = 3.62 (gate 3.0): alternate eclipses differ, so the true period is 2 x 5.8063 = 11.6125 d.