Follow-up Observation of TCP J17583414-2652300 Classifying as a Reddened Classical Nova

ATel #16038; Kenta Taguchi (Kyoto University)
on 17 May 2023; 00:17 UT
Credential Certification: Keisuke Isogai (isogai@kusastro.kyoto-u.ac.jp)

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I report the spectroscopic classification and photometric observation of TCP J17583414-2652300. I obtained its spectra by the fiber-fed integral field spectrograph (KOOLS-IFU; Matsubayashi et al. 2019) mounted on the 3.8 m Seimei telescope (Kurita et al. 2020) at Okayama Observatory of Kyoto University on 2023-05-16.78 UT using the VPH-blue grism (covering 4100 - 8500 Å). I also performed multi-color photometry using the TriColor CMOS Camera and Spectrograph (TriCCS) on the same telescope on 2023-05-16.7789 UT.

My spectrum is dominated by a red continuum. Emission lines of Balmer (Hα and Hβ) and O I (7773 and 8446 Å) having P Cyg profiles are detected. Also, a possible He I line (6678 Å) is seen. From the features above, I propose the classification of this object as a classical nova. The red continuum suggests this object has highly reddened. Consistently, the lines of Na I D (5686 Å) and DIB (e.g., 5780 and 6284 Å) are detected.

According to my photometry, the magnitudes of this object are g = 15.71, r = 13.00, and i = 11.4, respectively. From the i-band image, the position of this object is ∼ (17:58:34.190, -26:52:29.33). Neither is Gaia DR3 4064006602222245888 (34.257, 28.48) nor Gaia DR3 4064006602222267776 (34.079, 27.80) likely the progenitor. According to ASAS-SN Sky Patrol (Shappee et al. 2014; Kochanek et al. 2017), this object was detected g = 17.162, 16.964, and 16.710 on 2023-05-11.2390666, 12.2799619, 14.3623983, respectively. Therefore, this object could have started the outburst more than five days before the discovery by Koichi Itagaki on 2023-05-16.6980 UT.

I appreciate Kosuke Namekata for sharing the observation time and cooperating with this ToO observation.

The spectrum