TIC 193548084
An uncatalogued eclipsing-binary candidate from TESS.
Eclipsing-binary candidate: 1.9061-day period (twice the BLS period), a 1.11% primary eclipse, a 0.57% secondary eclipse at phase 0.512. Automated cross-checks question this period - see below.
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 6,862x 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 12:49 UTC
- Primary2026-10-20 11:08 UTC
- Secondary2026-10-21 10:33 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 0.957% (observed minus binned median).
Automated cross-checks question this period - see Caveats below.
- Period
- 1.90609 d
- Primary depth
- 1.11%
- Secondary depth
- 0.57%
- Epoch (T0)
- 1684.504 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 75.
- 24.3
- 0.26 px5"
- 0.0225 phase
- TIC 1935480860.59 px, dT 4.8
- 0.82
- 75
The dimming is centred on the target star. No nearby contaminant detected.
- Centroid offset
- 0.26 px
- Difference SNR
- 24.3
- Capable neighbour
- TIC 193548086
- TESS sector
- 75
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 747 light years away: the light TESS recorded left it around 747 years ago.
Together the two stars give off about 2.0 times less light than the Sun in Gaia's band, before correcting for interstellar dust.
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 2083032617153179008.
Gaia's position measurements fit this source poorly (RUWE 10.89, above the usual 1.4). That often means more than one star is there - most likely a wider third star or an unresolved neighbour, since a tight eclipsing pair barely moves Gaia's image. Context, not confirmation.
- Distance
- 229 +/- 5 pc
- Light-travel time
- ~747 years
- Apparent G
- 12.25
- Absolute G
- 5.45
- Colour BP-RP
- 1.13
- RUWE
- 10.89
- Match offset
- 0.15 arcsec
The ground-survey check
An independent instrument, different years: does real ZTF photometry show the eclipse at the period TESS measured?
- ZTF g (729 pts, 94 outliers)Not significant (p=0.18)
Folded at the TESS-measured period of 0.95304 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
- 1.90609 d
- BLS period
- 0.95304 d
- Odd/even z
- 3.39
Caveats
Known limitations and things to check.
Cross-check:No eclipse at 28 of 123 covered epochs where the 1.90609 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 0.44548 d (Lomb-Scargle power 0.26); the adopted 1.90609 d is 4.28 x that. The true period is more likely 0.44548 d (pulsation or spots) or 0.89097 d (contact binary), and the 'eclipses' may not be eclipses.
- Period alias:Odd/even eclipse-depth z-score is 3.39 (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, 1.906087 d, in any write-up.
VIIIInstrument
Raw values, fits and technical details.
Instrument
Raw values, fits and technical details.
Full statistics
- 1.90609 d
- 0.95304 dalias
- 1.11% +/- 0.08%seen 53/123
- ML screening score
- 0.178logistic_regression
- 0.57% +/- 0.01%phase 0.512, 42 sigma
- 3.39> 3: alias
- 0.4455 dpower 0.26 - FLAG
- 5.9 h
- Distance (TIC, Gaia-based)
- -
- 12.25 / 11.67
- - / -
- RA / Dec (J2000)
- 20h 24m 9.2s +46d 10m 26s
- 83.1 / 24.3
- 65,918 ptsover 1901 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 = 3.39 (gate 3.0): alternate eclipses differ, so the true period is 2 x 0.9530 = 1.9061 d.
O - C timing
48 eclipses timed, rms 151.32 min, reduced chi-square 5844.97 (46 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 = 1.906283 +/- 0.000001 d.