Variable dust emission by WC type Wolf-Rayet stars observed in the NEOWISE-R survey

Abstract

Photometry at 3.4 and 4.6 micron of 128 Population~I WC type Wolf-Rayet stars in the Galaxy and 12 in the Large Magellanic Cloud (LMC) observed in the WISE NEOWISE-R survey was searched for evidence of circumstellar dust emission and its variation. Infrared spectral energy distributions (SEDs) were assembled, making use of archival r, i, Z and Y photometry to determine reddening and stellar wind levels for the WC stars found in recent IR surveys and lacking optical photometry. From their SEDs, ten apparently non-variable stars were newly identified as dust makers, including three, WR 102-22, WR 110-10 and WR 124-10, having subtype earlier than WC8-9, the first such stars to show this phenomenon. The 11 stars found to show variable dust emission include six new episodic dust-makers, WR 47c, WR 75-11, WR 91-1, WR 122-14 and WR 125-1 in the Galaxy and HD 38030 in the LMC. Of previously known dust makers, NEOWISE-R photometry of WR 19 captured its rise to maximum in 2018, confirming the 10.1-y period, that of WR 125 the beginning of a new episode of dust formation suggesting a period near 28.3~y., while that of HD 36402 covered almost a whole period and forced revision of it to 5.1~y.

accepted to MNRAS

References in corpus (16)

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Cited by in corpus (14)

• Quantifying Variability of YSOs in the Mid-IR Over Six Years with NEOWISE
• unTimely: a Full-sky, Time-Domain unWISE Catalog
• Revisiting the Impact of Dust Production from Carbon-Rich Wolf-Rayet Binaries
• Analysis of physical processes in eruptive YSOs with near infrared spectra and multi-wavelength light curves
• A spectroscopic multiplicity survey of Galactic Wolf-Rayet stars: II. The northern WNE sequence
• Revealing Efficient Dust-Formation at Low Metallicity in Extragalactic Carbon-Rich Wolf-Rayet Binaries
• An exploration of dust grain growth within WCd systems using an advected scalar dust model
• Quest for the upcoming periastron passage of an episodic dust maker and particle accelerating colliding wind binary: WR 125
• UV Spectropolarimetry with Polstar: Massive Star Binary Colliding Winds
• The episodic dust-making Wolf-Rayet star HD 38030 in the Large Magellanic Cloud
• The Galactic Center in Color: Measuring Extinction with High-Proper-Motion Stars
• Investigation of [KSF2015] 1381-19L, a WC9-type star in the high extinction Galactic region
• Discovery of a 310-day Period from the Enshrouded Massive System NaSt1 (WR 122)
• Multiwavelength view of massive binaries