Star Vetter

TIC 313498432

An uncatalogued eclipsing-binary candidate from TESS.

Period aliasSurvivorP = 54.88825 d

Eclipsing-binary candidate: 54.8882-day period (twice the BLS period), a 0.13% primary eclipse, a 0.07% secondary eclipse at phase 0.552.

TIC 313498432 is a candidate eclipsing binary star detected in TESS photometry with an orbital period of 54.888249 days and a primary eclipse depth of 0.10% dimming. The automated transit-search pipeline identified this target with a detection significance of 38.7 and a machine-learning confidence score of 0.96. Pixel-level image analysis confirmed the signal at a peak signal-to-noise of 9.6, though the centroid offset of 17.5 arcsec warrants attention. No secondary eclipse was detected. The target does not appear in six major variable-star catalogs. However, an automated data-quality check found that alternating eclipses differ significantly in depth - a pattern suggesting the true orbital period may be twice the initially measured value. While pixel-confirmation and eclipse timing remain unaffected by this finding, the alternating-depth signature represents an open question about the system's true nature.

Primary eclipsetotal light 0.999
Surface brightness ratio
0.55
Companion temperature
~4,090 K
Companion / star radius
~0.08
Face hidden at primary eclipse
~1%
Separation
~157 x the star's radius
Eccentricity
at least 0.082
Secondary eclipse phase
0.552 measured, 0.552 in this orbit

Zoomed: both stars drawn about 35x 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 (4,710 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 197,598x 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.

  • Secondary2026-10-30 03:01 UTC
  • Primary2026-11-23 17:11 UTC
  • Secondary2026-12-24 00:20 UTC

Computed from the fitted ephemeris. Approximate - not corrected for your location or for light-travel time across Earth's orbit.

I

The signal

A repeating, consistent dip in brightness.

observed binned median residuals
0.99850.99900.99951.00001.00051.00101.00150-0.4-0.20.00.20.4phase (P = 54.8882 d)relative flux

Residual scatter 0.051% (observed minus binned median).

!

Alternate eclipses differ in depth, so the true period is twice the search period.

Period
54.88825 d
Primary depth
0.13%
Secondary depth
0.07%
Epoch (T0)
2831.345 BTJD
Duration
2.88 h
II

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
III

The pixel check

Confirms the dimming is on the target star, not a nearby source.

Out of eclipse
In eclipse
Difference (out - in)
+ target TIC 313498432x neighbour bright enough to cause the dipo other TIC starsO dimming centroid1 pixel = 21"

Out/in share one sqrt colour scale; in-eclipse = out-of-eclipse minus difference. TESS sector 56.

9.6
0.83 px17"
-0.0500 phase
TIC 3134984302.27 px, dT 6.5
0.87
56

The dimming is centred on the target star. No nearby contaminant detected.

Centroid offset
0.83 px
Difference SNR
9.6
Capable neighbour
TIC 313498430
TESS sector
56
IV

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.

V

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.

VI

Fold it yourself

Adjust the period and watch the eclipse appear.

0.99850.99900.99951.00001.00051.00101.0015-0.4-0.20.00.20.4phaserelative flux
54.88825

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
54.88825 d
BLS period
27.44412 d
Odd/even z
3.07
VII

Caveats

Known limitations and things to check.

  • Period alias:Odd/even eclipse-depth z-score is 3.07 (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, 54.888249 d, in any write-up.
VIII

Instrument

Raw values, fits and technical details.

Show raw data

Full statistics

54.88825 d
27.44412 dalias
0.13% +/- 0.01%seen 2/2
ML screening score
0.961logistic_regression
0.07% +/- 0.01%phase 0.552, 10 sigma
3.07> 3: alias
0.4106 dpower 0.03
2.9 h
Distance (TIC, Gaia-based)
463 pc+/- 7
8.92 / 8.28
4710 K / 11.05 Rsun
RA / Dec (J2000)
16h 36m 45.6s +53d 29m 48s
38.7 / 9.6
39,742 ptsover 759 d

Eclipse close-ups

Primary eclipse0.13%
0.99800.99901.00001.0010-505hours from mid-eclipse
Secondary (phase 0.552)0.07%
0.99800.99901.00001.0010-505hours from mid-eclipse

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

BLS period 27.4441 d
0.99901.00001.0010-0.50.00.5
2x BLS 54.8882 d
0.99901.00001.0010-0.50.00.5

Odd/even depth z = 3.08 (gate 3.0): alternate eclipses differ, so the true period is 2 x 27.4441 = 54.8882 d.

O - C timing

primary eclipses
only 2 fully-covered eclipse(s) in the data - at least 3 are needed to test the period for timing changes

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