TIC 405525689

Transit candidateRare, already known

Rare & notable finds

Something genuinely unusual turned up. Treat it as a lead: every one of these has ordinary explanations too, listed with each. How these checks work →

Already known: in SIMBAD as TYC 3867-584-1 (*); the catalogued variable PU Dra (EA, 85" away) has the same period - its light leaks into TESS's big pixels; same period as the known variable PU Dra. The rare-find check confirms what is on record - still nice, but not a new discovery.

Microlensing (rogue planet?) significant
A one-off, symmetric brightening at BTJD 3385.54 that fits the gravitational-lens shape better than a flare (Einstein time 16.2 h). Events this short can be made by a free-floating (rogue) planet passing in front of the star. Very rare in TESS data; scattered light and asteroids can mimic it.

Checked, nothing found (8)

Exocomet-shaped dip · Habitable zone & size · Transit timing (TTV) · Transit duration (TDV) · Changing transit depth · Lopsided transit · Dimming beside the transit · Type of star

Checked 2026-10-11 16:57 on NVIDIA GeForce RTX 4070, using every TESS sector of this star. All results (.json)

Notes

Probably noise or an instrument effect. Rare, already known: Microlensing (rogue planet?) (in SIMBAD as TYC 3867-584-1 (*); the catalogued variable PU Dra (EA, 85" away) has the same period - its light leaks into TESS's big pixels). WARNING: same period as the known variable PU Dra 85" away; the signal is probably its light leaking in. Found automatically by hunt.py in TESS sector 23 (flagged in 2 sector(s)). Detection score 92.9. Not in VSX, ASAS-SN or ZTF variable catalogues at the time of the search; not in Gaia DR3's variable lists. Unchecked by hand yet: verify the period, nearby stars and a wider catalogue search. Updates: 2026-10-11 Planet check: Probably noise or an instrument effect 2026-10-11 Rare-find check: Microlensing (rogue planet?) 2026-10-11 Found by the automatic search in TESS sector 23

The signal

Type	Transit candidate
Status	Rare, already known
Period (days)	1.54504
Period source	hunt.py on TESS QLP sector 23
Eclipse / dip depth	2.1%
Amplitude	2.5%
Data used	TESS sector 23 (QLP)

Planet check

Verdict	Probably noise or an instrument effect ExoFOP check plot all test results light curve data
Size if it's a planet	~17.0 Earth radii (~1.52 Jupiter)

The star (Gaia & TESS)

Distance (pc)	196 (~638 light years)
Temperature (Gaia)	5,765 K
Size (Gaia)	1.09 x the Sun
Mass (Gaia)	0.98 x the Sun
Luminosity (Gaia)	1.20 x the Sun
Colour, Gaia BP-RP	0.80
RUWE (Gaia)	0.94 - fits a single star
Gaia G mag	10.95
TESS mag	10.52

Names & neighbours

TIC ID	405525689
Gaia DR3 ID	1613991367729831936
SIMBAD name	TYC 3867-584-1 [*]
Nearest known variable	PU Dra (EA, P = 1.5456 d), 85" away (same period!)
RA (deg)	225.204
Dec (deg)	57.7694
Look it up	SIMBAD · VSX · ESASky · ExoFOP

Record

Found by	hunt.py (automatic)
Date	2026-10-11
Last update	2026-10-11

Where it sits among the stars

ESA Gaia colour and true brightness. Grey: every Star Log candidate. Orange: this star.

How to read this diagram →

Data files

Download everything (.zip)