Case file OS-0034 · NGC 3344 periodic IR source · reproduced

A source in NGC 3344 next to Wolf-Rayet stars that flares in the infrared about every 10 years, like the dust maker WR 140

Found blind by Oddsky's search for repeating infrared sources (hunt H-0013): sharp infrared outbursts in 2004, 2014 and 2023, each lasting about a year and a half over a flat minimum, on a young star cluster whose spectrum shows Wolf-Rayet features. Next outburst expected around 2033.

An infrared source in the spiral galaxy NGC 3344 (6.9 Mpc) that flares for about a year and a half roughly every 10 years (2004, 2014, 2023), on a young cluster whose spectrum shows Wolf-Rayet stars. It looks like a scaled-up WR 140, a binary that makes dust each time its stars swing close. Next outburst expected around 2033. Found blind by Oddsky hunt H-0013.

Claims

• C1 [observed] Spitzer/IRAC: +80 uJy above quiescence at 2004.32 in both bands; quiescent 2012.5-2013.1; a rise caught at 2013.18 and a peak at 2014.1 (+85 uJy); quiescent again by 2016. WISE: flat 2016-2022, then a new outburst peaking about 2023.3 (hunts/H-0013/README.md).
• C2 [computed] Outbursts spaced 9.8 and about 9.2 yr, each lasting about 1.5 yr (duty cycle about 0.15) with a fast rise: the morphology of WR 140. Peak nu Lnu(W2) about 1e5 Lsun at 6.85 Mpc, about 30x WR 140. The Spitzer variable is a point source 0.45" from the WISE position.
• C3 [observed] It lies 0.4" from [BKD2008] WR 541, an SDSS fibre spectrum with Wolf-Rayet features (Brinchmann, Kunth & Durret 2008), on a blue knot (Gaia G = 21.1, BP-RP about 0, MG about -8: a young cluster). The WR signature belongs to a 3" (about 100 pc) fibre, not necessarily to this star.
• C4 [observed] Caveat: the 2004 outburst rests on a single Spitzer epoch.
• C5 [observed] Not reported (2026-11-02): ADS full text for the coordinates and for the host with variability terms finds nothing on this source; nothing in TNS, SIMBAD, Gaia DR3, AllWISE or the Spitzer SEIP catalogue at the position; the SPIRITS catalogue of luminous long-period variables (Karambelkar et al. 2019) does not cover this galaxy.

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