TIC 355828577
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 0.9515-day period, a 17.93% primary eclipse, a 1.59% secondary eclipse at phase 0.163. Automated cross-checks question this period - see below.
TIC 355828577 is a candidate eclipsing binary star with an orbital period of 0.9515 days. Data from NASA's TESS mission shows a primary eclipse causing the star to dim by 1.40 percent, detected with a signal-to-noise ratio of 33.7 using the Box Least Squares algorithm. Pixel-level analysis confirms this signal at a peak signal-to-noise of 10.9, though with a centroid offset of 3.9 arcsec from the target location. No secondary eclipse was detected in the available data. This candidate does not appear in six major variable-star catalogs, making it a novel find. The automated machine-learning screening assigned it a score of 0.28 on a scale where higher values indicate greater confidence in the target's validity.
This light curve is smooth and sinusoidal rather than eclipse-shaped - typical of a close pair distorted by each other's gravity, or of a signal that is not an eclipse - so the eclipse-geometry estimates do not apply. The drawing is generic; the glow still follows the real light curve.
Not to scale. 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 are illustrative. Only the relative orbit is shown; both stars really circle their common centre of mass. Animated about 3,425x 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 11:23 UTC
- Secondary2026-10-19 15:06 UTC
- Primary2026-10-20 10:13 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 1.600% (observed minus binned median).
Automated cross-checks question this period - see Caveats below.
- Period
- 0.95148 d
- Primary depth
- 17.93%
- Secondary depth
- 1.59%
- Epoch (T0)
- 1684.066 BTJD
- Duration
- 1.39 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 74.
- 10.9
- 0.19 px4"
- 0.1700 phase
- none
- 0.79
- 74
The dimming is centred on the target star. No nearby contaminant detected.
- Centroid offset
- 0.19 px
- Difference SNR
- 10.9
- Capable neighbour
- none
- TESS sector
- 74
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?
The latest ground-survey file does not include this candidate yet, so there is no independent ZTF check to show.
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
- 0.95148 d
- BLS period
- 0.95148 d
- Odd/even z
- 0.36
Caveats
Known limitations and things to check.
Cross-check:No eclipse at 109 of 110 covered epochs where the 0.95148 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.
Cross-check:The light curve is dominated by a smooth sinusoid with period 0.15872 d (Lomb-Scargle power 0.33); the adopted 0.95148 d is 5.99 x that. The true period is more likely 0.15872 d (pulsation or spots) or 0.31743 d (contact binary), and the 'eclipses' may not be eclipses.
VIIIInstrument
Raw values, fits and technical details.
Instrument
Raw values, fits and technical details.
Full statistics
- 0.95148 d
- 0.95148 dsame
- 17.93% +/- 3.57%seen 1/110
- ML screening score
- 0.282logistic_regression
- 1.59% +/- 0.06%phase 0.163, 26 sigma
- 0.36< 3
- 0.1587 dpower 0.33 - FLAG
- 1.4 h
- Distance (TIC, Gaia-based)
- 190 pc
- - / 11.28
- - / -
- RA / Dec (J2000)
- 10h 07m 57.6s +65d 29m 31s
- 33.7 / 10.9
- 26,012 ptsover 1656 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 = 0.36 (gate 3.0): alternate eclipses match, so the BLS period stands.