TIC 232261044
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 1.6216-day period (twice the BLS period), a 3.32% primary eclipse, a 2.85% secondary eclipse at phase 0.493.
TIC 232261044 is a candidate eclipsing binary star detected in automated TESS photometry with an orbital period of 1.621641 days and a primary eclipse depth of 2.53 percent. The detection shows a high signal-to-noise ratio of 88.5 in the periodogram analysis, and pixel-level difference imaging confirms a peak signal-to-noise of 13.1. However, important caveats affect this result: the centroid offset of 2.6 arcsec places the dimming signal very close to a nearby bright star, within TESS's resolution limits, making it difficult to confidently attribute the eclipse to TIC 232261044 rather than its neighbor. Additionally, the alternating eclipse depths show a statistically significant variation that suggests the true orbital period may be double the initially measured value. The candidate does not appear in six major variable-star catalogs, but verification of its nature and precise characterization will require observations beyond automated pipeline analysis.
- Surface brightness ratio
- 0.86
- Companion temperature
- ~6,042 K
- Companion / star radius
- ~0.18
- Face hidden at primary eclipse
- ~3%
- Separation
- ~5.1 x the star's radius
- Eccentricity
- at least 0.011
- Secondary eclipse phase
- 0.493 measured, 0.493 in this orbit
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 (6,348 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 5,838x 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 11:13 UTC
- Primary2026-10-20 06:56 UTC
- Secondary2026-10-21 02:08 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 0.552% (observed minus binned median).
Alternate eclipses differ in depth, so the true period is twice the search period.
- Period
- 1.62164 d
- Primary depth
- 3.32%
- Secondary depth
- 2.85%
- Epoch (T0)
- 1468.349 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.
- 13.1
- 0.12 px3"
- 0.0025 phase
- TIC 7136658680.20 px, dT 0.6
- 0.94
- 6
The dimming centroid sits almost as close to a bright neighbour as to the target.
- Centroid offset
- 0.12 px
- Difference SNR
- 13.1
- Capable neighbour
- TIC 713665868
- 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 9,048 light years away: the light TESS recorded left it around 9,048 years ago.
Together the two stars give off about 9.0 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 3318238960630132864.
Gaia's measurements fit a single point of light well (RUWE 1.08), as expected for a pair too close for Gaia to separate.
- Distance
- 2,774 +/- 212 pc
- Light-travel time
- ~9,048 years
- Apparent G
- 14.50
- Absolute G
- 2.29
- Colour BP-RP
- 0.97
- RUWE
- 1.08
- Match offset
- 0.03 arcsec
The ground-survey check
An independent instrument, different years: does real ZTF photometry show the eclipse at the period TESS measured?
- ZTF g (150 pts, 43 outliers)Confirmed (p=<0.0001)
- ZTF r (237 pts, 93 outliers)Confirmed (p=<0.0001)
Folded at the TESS-measured period of 0.81082 d, every band shows individual ZTF epochs - real observations, years apart - landing far below the baseline brightness and clustered in phase far tighter than chance would produce given how many such epochs that band has (p < 0.01, chance-corrected for the outlier count).
Source: ZTF public light-curve archive (IRSA), independent of the TESS data used to detect this candidate.
Real ZTF ground-survey photometry backs this period: 2 bands show epochs, years apart, landing more than 5 sigma below the baseline brightness and clustered in phase far tighter than chance would produce given how many such epochs that band has (p < 0.01) - a different instrument finding the same eclipse.
- Bands confirmed
- ZTF g, ZTF r
- Deepest clustered dip
- 48.7 sigma (ZTF r)
- Chance p-value
- < 0.0001 (ZTF g)
- Period tested
- 0.81082 d
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
- 1.62164 d
- BLS period
- 0.81082 d
- Odd/even z
- 5.53
Caveats
Known limitations and things to check.
- Period alias:Odd/even eclipse-depth z-score is 5.53 (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, 1.621641 d, in any write-up.
- Thin margin:The ON_TARGET call rests on a neighbour-competition margin of just 0.075 px (dimming centroid 0.125 px from target vs 0.200 px from the nearest bright-enough neighbour) - inside diag_pixel.py's own stated centroid systematic of 0.10-0.3 px. TESS's resolution cannot confidently separate this star from that neighbour.
VIIIInstrument
Raw values, fits and technical details.
Instrument
Raw values, fits and technical details.
Full statistics
- 1.62164 d
- 0.81082 dalias
- 3.32% +/- 0.09%seen 10/10
- ML screening score
- 0.427logistic_regression
- 2.85% +/- 0.08%phase 0.493, 35 sigma
- 5.53> 3: alias
- 0.8116 dpower 0.38
- 2.9 h
- Distance (TIC, Gaia-based)
- 2877 pc+/- 454
- 14.52 / 14.01
- 6348 K / 3.48 Rsun
- RA / Dec (J2000)
- 06h 07m 9.0s +04d 32m 39s
- 88.5 / 13.1
- 904 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 = 5.53 (gate 3.0): alternate eclipses differ, so the true period is 2 x 0.8108 = 1.6216 d.
O - C timing
9 eclipses timed, rms 4.99 min, reduced chi-square 10.46 (7 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 = 1.623884 +/- 0.000064 d.