Abstract: An outburst of the February Hydrids meteor shower (FHY#1032) was detected in CAMS data during February 11-17. The meteoroids originated from an unidentified Jupiter family comet. The shower was previously detected in 2013 and 2018. The periodicity is consistent with dust trapped in the 5:2 mean motion resonance with Jupiter.
Introduction
The February Hydrids (IAU shower FHY#1032) is a Jupiter-family comet shower that was first recognized in 2018 from twelve triangulated orbits (Jenniskens et al., 2018a,b). Three meteors were also triangulated in 2013, but in other years this shower is mostly absent.
In 2023, the global Cameras for Allsky Meteor Surveillance (CAMS) low-light video-camera networks detected an outburst of the February Hydrid meteors (shower FHY#1032) (Jenniskens, 2023).
Figure 1. February Hydrid shower (From: https://meteorshowers.seti.org).
The 2023 outburst
The shower was not prominent in any of the individual CAMS networks, but a large number of networks recorded a few shower members. The following camera networks detected this shower: CAMS California (coordinated by J. Albers, E. Egland, B. Grigsby, and T. Beck), CAMS Florida (A. Howell), CAMS BeNeLux (C. Johannink, M. Breukers), Lowell Observatory CAMS (N. Moskovitz, S. Hemmelgarn, and B. Rachford), United Arab Emirates Astronomical Camera Network (M. Odeh), CAMS Arkansas (L. Juneau, S. Austin), CAMS Australia (M. Towner, D. Rollinson), CAMS Chile (S.Heathcote, E. Jehin, and T. Abbott), CAMS Namibia (T. Hanke, E. Fahl, R. van Wyk), and CAMS Texas (W. Cooney).
In the period of February 11–17, a total of twenty-nine February Hydrid meteors were triangulated during the solar longitude interval of 321.9° – 327.2° (equinox J2000.0) (See Figure 1). The median orbit of 2023 is compared with that of 2018 in Table 1.
Table 1 – The median orbital elements, and their standard error on the median, for the orbits of the February Hydrids (FHY#1032) triangulated in 2023, compared to those measured in 2018 (Jenniskens et al., 2018b).
| 2018 | 2023 | |
| λʘ (°) | 324.3 | 324.6 |
| αg (°) | 123.9 | 123.8 ± 0.1 |
| δg (°) | +1.5 | +0.4 ± 0.2 |
| vg (km/s) | 16.4 | 16.4 ± 0.1 |
| λ – λʘ (°) | 161.6 | 160.7 |
| β (°) | –17.8 | -18.9 |
| a (AU) | 2.68 | 2.80 ± 0.08 |
| q (AU) | 0.812 | 0.8223 ± 0.0018 |
| e | 0.697 | 0.705 ± 0.006 |
| ω (°) | 55.5 | 53.7 ± 0.2 |
| Ω (°) | 144.3 | 145.4 ± 0.2 |
| i (°) | 8.3 | 8.6 ± 0.1 |
| Π (°) | 199.8 | 199.1 |
| N | 17 | 29 |
Figure 2 – The concentration of February Hydrid radiants detected by the Global Meteor Network (http://globalmeteornetwork.org). Image courtesy of P. Roggemans.
Discussion
The activity of this shower was also detected by the Global Meteor Network, based on public data (Figure 2). In recent years, GMN networks have grown around CAMS BeNeLux, LO-CAMS and CAMS Australia, but the other CAMS networks above provide an independent detection.
The nearly 5-year periodicity of the returns and the 2.8 AU semi-major axis suggests that the shower is due to dust trapped in the 5:2 mean-motion resonance with Jupiter, with a corresponding 4.7-year periodicity. If so, the next return will be in 2027 and/or 2028.
References
Jenniskens P., Johannink C., Moskovitz N. (2018a). “February Hydrids outburst (IAU#1032, FHY)”. WGN, Journal of the International Meteor Organization, 46, 85–86.
Jenniskens P., Baggaley J., Crumpton I., Aldous P., Pokorny P., Janches D., Gural P. S., Samuels D., Albers J., Howell A., Johannink C., Breukers M., Odeh M., Moskovitz N., Collison J. and Ganjuag S. (2018b). “A survey of southern hemisphere meteor showers”. Planetary Space Science, 154, 21–29.
Jenniskens P. (2023). “February Hydrid meteors 2023”. CBET 5231,edited by Daniel W. E. Green, 2023 March 6.
