Nova V488 Sge Is Forming Dust
ATel #18129; Kishalay De (Columbia University), Laura Chomiuk (Michigan State University), Peter Craig (Michigan State University), Salma Ibrahim (Columbia University), Stella Manyan (Columbia University) and David Schiminovich (Columbia University)
on 29 Oct 2026; 22:21 UT
Credential Certification: Laura Chomiuk (chomiuk@pa.msu.edu)
Subjects: Infra-Red, Nova
Galactic classical nova V488 Sge was discovered on 2026 Aug 25 (CBET #5729, ATel #18008), and has been the subject of intensive AAVSO photometric coverage in the optical bands. There is no sign of a dust dip in the optical.
We have been monitoring V488 Sge in the near-IR (J and Hs bands) using the robotic MDM-Infrared InGaAs Experiment (MIRAGE) camera on the 1.3m telescope at the MDM observatory. We obtained 7 epochs of J+Hs photometry between 2026-09-11 and 2026-10-27, showing that the nova steadily faded from J = 8.45 +/- 0.01 Vega mag to J = 10.59 +/- 0.01 mag. In our most recent epochs obtained between Oct 20 and Oct 27, its IR colors became significantly redder from J-Hs ~ 0 mag to J-Hs ~ 0.7 mag, signalling that this nova is forming dust. It is likely a member of the "IR Excess" category of novae (Gehrz 1988 ARA&A, 26, 377; Chong et al. 2025, MNRAS, 541, 980), which show signatures of dust formation in the IR but not in the optical.
Link to optical + IR light curve
