TIC 390650992

Transit candidateRare, already known

Rare & notable finds

Something unusual, worth a look - less certain than a significant find. How these checks work →

Already known: in SIMBAD as UCAC4 503-057012 (PM*); catalogued variable star nearby: Gaia DR3 3927299923457038592 (ROT), 77" away. The rare-find check confirms what is on record - still nice, but not a new discovery.

Ultra-short-period planet notable
One orbit takes 6.4 hours - ultra-short-period planets are found around only ~0.5% of stars (if the signal is a real planet - it hasn't passed the planet check).
Hot Neptune desert notable
A 5.2 Earth-radius planet on a 0.26-day orbit sits in the 'hot Neptune desert', where very few planets are known (if the signal is a real planet - it hasn't passed the planet check).
Lopsided transit hint
The start of the transit is deeper than the end: a dust tail (disintegrating planet), rings, a fast-spinning star, or a blend.

Checked, nothing found (5)

Microlensing (rogue planet?) · Exocomet-shaped dip · Habitable zone & size · Transit timing (TTV) · Type of star

Checked 2026-10-11 17:04 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: Ultra-short-period planet; Hot Neptune desert; Lopsided transit (in SIMBAD as UCAC4 503-057012 (PM*); catalogued variable star nearby: Gaia DR3 3927299923457038592 (ROT), 77" away). Found automatically by hunt.py in TESS sector 23 (flagged in 1 sector(s)). Detection score 62.0. 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: Lopsided transit; Ultra-short-period planet; Hot Neptune desert 2026-10-11 Found by the automatic search in TESS sector 23

The signal

Type	Transit candidate
Status	Rare, already known
Period (days)	0.264983
Period source	hunt.py on TESS QLP sector 23
Eclipse / dip depth	1.3%
Amplitude	1.6%
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	~5.4 Earth radii (~0.48 Jupiter)

The star (Gaia & TESS)

Distance (pc)	76 (~249 light years)
Colour, Gaia BP-RP	2.23
RUWE (Gaia)	1.09 - fits a single star
Gaia G mag	13.54
TESS mag	12.46

Names & neighbours

TIC ID	390650992
Gaia DR3 ID	3927300232694684160
SIMBAD name	UCAC4 503-057012 [PM*]
Nearest known variable	Gaia DR3 3927299923457038592 (ROT), 77" away
RA (deg)	191.886
Dec (deg)	10.4996
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)