TIC 422540997

Eclipsing binaryNotable, already known

Rare & notable finds

A notable find: not unheard of, but the kind of system astronomers are glad to have more of. How these checks work →

Already known: the catalogued variable BU Cas (EA/DM, 47" away) has the same period - its light leaks into TESS's big pixels; same period as the known variable BU Cas. The rare-find check confirms what is on record - still nice, but not a new discovery.

Transits of a giant star notable
Gaia places this star among the giants: planets transiting giants are rare, and a big star makes even a large planet's dip tiny.

Checked, nothing found (6)

Microlensing (rogue planet?) · Exocomet-shaped dip · Eclipse timing (third body?) · Eclipses changing depth · Pulsating star in an eclipsing binary · Extra dips outside the eclipses

Checked 2026-10-11 18:24 on NVIDIA GeForce RTX 4070, using every TESS sector of this star. All results (.json)

Notes

Notable, already known: Transits of a giant star (the catalogued variable BU Cas (EA/DM, 47" away) has the same period - its light leaks into TESS's big pixels; same period as the known variable BU Cas). WARNING: same period as the known variable BU Cas 47" away; the signal is probably its light leaking in. Found automatically by hunt.py in TESS sector 18 (flagged in 1 sector(s)). Detection score 1542.9. 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 Rare-find check: Transits of a giant star 2026-10-10 Gaia hints at a hidden companion star (RUWE 1.5) 2026-10-10 Found by the automatic search in TESS sector 18

The signal

Type	Eclipsing binary
Status	Notable, already known
Period (days)	4.52458
Period source	hunt.py on TESS QLP sector 18
Eclipse / dip depth	56.4%
Amplitude	46.2%
Data used	TESS sector 18 (QLP)

The star (Gaia & TESS)

Distance (pc)	3,712 (~12,109 light years)
Temperature (Gaia)	5,139 K
Size (Gaia)	15.19 x the Sun
Mass (Gaia)	3.10 x the Sun
Luminosity (Gaia)	123.18 x the Sun
Colour, Gaia BP-RP	2.05
RUWE (Gaia)	1.53 - hints at a hidden companion star
Gaia G mag	13.92
TESS mag	12.92

Names & neighbours

TIC ID	422540997
Gaia DR3 ID	510650381482684672
SIMBAD name	not in SIMBAD
Nearest known variable	BU Cas (EA/DM, P = 2.2552 d), 47" away (same period!)
RA (deg)	22.1946
Dec (deg)	61.1381
Look it up	SIMBAD · VSX · ESASky · ExoFOP

Record

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