An optical transient candidate of $\lesssim$ 2-second duration captured by wide-field video observations

Fuente: arXiv
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Autores principales: Arima, Noriaki, Doi, Mamoru, Sako, Shigeyuki, Niino, Yuu, Ohsawa, Ryou, Tominaga, Nozomu, Tanaka, Masaomi, Richmond, Michael, Abe, Shinsuke, Kobayashi, Naoto, Kondo, Sohei, Mori, Yuki, Arimatsu, Ko, Kasuga, Toshihiro, Okumura, Shin-ichiro, Watanabe, Jun-ichi, Yamashita, Takuya
Formato: Preprint
Publicado: 2026
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author Arima, Noriaki
Doi, Mamoru
Sako, Shigeyuki
Niino, Yuu
Ohsawa, Ryou
Tominaga, Nozomu
Tanaka, Masaomi
Richmond, Michael
Abe, Shinsuke
Kobayashi, Naoto
Kondo, Sohei
Mori, Yuki
Arimatsu, Ko
Kasuga, Toshihiro
Okumura, Shin-ichiro
Watanabe, Jun-ichi
Yamashita, Takuya
author_facet Arima, Noriaki
Doi, Mamoru
Sako, Shigeyuki
Niino, Yuu
Ohsawa, Ryou
Tominaga, Nozomu
Tanaka, Masaomi
Richmond, Michael
Abe, Shinsuke
Kobayashi, Naoto
Kondo, Sohei
Mori, Yuki
Arimatsu, Ko
Kasuga, Toshihiro
Okumura, Shin-ichiro
Watanabe, Jun-ichi
Yamashita, Takuya
contents Recent time-domain surveys have revealed rapid transients that evolve on timescales of $\lesssim 10$ days, expanding the transient population into the short-duration regime. The transient search on even shorter timescales, particularly those lasting only seconds or less, remains a largely unexplored frontier. Very short-duration optical transients could serve as potential counterparts to millisecond-duration fast radio bursts (FRBs), providing clues to their origins. However, the optical search for transients on such short timescales has been limited primarily by instrumental constraints. Here we report the discovery of an optical transient candidate (TMG20200322) with a duration of $\lesssim 2$~s by wide-field video observations in the direction of the Earth's shadow. TMG20200322 was detected in just two consecutive images of 1-second exposure time, with its shape becoming elongated in the second frame. PSF shape variability analysis of field stars reveals that such an elongated PSF cannot be explained by atmospheric fluctuations. We investigate the potential origins of TMG20200322 in two scenarios: meteoroid impact flashes on near-Earth asteroids (NEAs) and head-on meteors in the Earth's atmosphere. None of the scenarios provides a satisfactory explanation for this transient. We derive a sky-projected rate of the TMG20200322 event of $R_{\mathrm{trans}} = (3.4 \times 10^{-2})^{+0.13}_{-0.028}$~deg$^{-2}$~day$^{-1}$ and an upper limit on second-timescale transients with durations of $1~\mathrm{s} \leq τ\lesssim 15~\mathrm{s}$ of $R_{\mathrm{trans}} \lesssim 0.10$~deg$^{-2}$~day$^{-1}$ for the non-detection case. We highlight that continuous monitoring observations in the direction of the Earth's shadow could be a key strategy to unveil a new population of optical transients on timescales of seconds or less.
format Preprint
id arxiv_https___arxiv_org_abs_2602_11600
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle An optical transient candidate of $\lesssim$ 2-second duration captured by wide-field video observations
Arima, Noriaki
Doi, Mamoru
Sako, Shigeyuki
Niino, Yuu
Ohsawa, Ryou
Tominaga, Nozomu
Tanaka, Masaomi
Richmond, Michael
Abe, Shinsuke
Kobayashi, Naoto
Kondo, Sohei
Mori, Yuki
Arimatsu, Ko
Kasuga, Toshihiro
Okumura, Shin-ichiro
Watanabe, Jun-ichi
Yamashita, Takuya
Earth and Planetary Astrophysics
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
Recent time-domain surveys have revealed rapid transients that evolve on timescales of $\lesssim 10$ days, expanding the transient population into the short-duration regime. The transient search on even shorter timescales, particularly those lasting only seconds or less, remains a largely unexplored frontier. Very short-duration optical transients could serve as potential counterparts to millisecond-duration fast radio bursts (FRBs), providing clues to their origins. However, the optical search for transients on such short timescales has been limited primarily by instrumental constraints. Here we report the discovery of an optical transient candidate (TMG20200322) with a duration of $\lesssim 2$~s by wide-field video observations in the direction of the Earth's shadow. TMG20200322 was detected in just two consecutive images of 1-second exposure time, with its shape becoming elongated in the second frame. PSF shape variability analysis of field stars reveals that such an elongated PSF cannot be explained by atmospheric fluctuations. We investigate the potential origins of TMG20200322 in two scenarios: meteoroid impact flashes on near-Earth asteroids (NEAs) and head-on meteors in the Earth's atmosphere. None of the scenarios provides a satisfactory explanation for this transient. We derive a sky-projected rate of the TMG20200322 event of $R_{\mathrm{trans}} = (3.4 \times 10^{-2})^{+0.13}_{-0.028}$~deg$^{-2}$~day$^{-1}$ and an upper limit on second-timescale transients with durations of $1~\mathrm{s} \leq τ\lesssim 15~\mathrm{s}$ of $R_{\mathrm{trans}} \lesssim 0.10$~deg$^{-2}$~day$^{-1}$ for the non-detection case. We highlight that continuous monitoring observations in the direction of the Earth's shadow could be a key strategy to unveil a new population of optical transients on timescales of seconds or less.
title An optical transient candidate of $\lesssim$ 2-second duration captured by wide-field video observations
topic Earth and Planetary Astrophysics
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2602.11600