J/A+A/687/A14 Lunar impact flashes monitoring (Liakos+, 2024)
NELIOTA: New results and updated statistics after 6.5 years of lunar impact
flashes monitoring.
Liakos A., Bonanos A.Z., Xilouris E.M., Koschny D., Bellas-Velidis I.,
Boumis P., Maroussis A., Moissl R.
<Astron. Astrophys., 687, A14 (2024)>
=2024A&A...687A..14L 2024A&A...687A..14L (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Meteorites ; Photometry ; Optical
Keywords: techniques: photometric - meteorites, meteors, meteoroids - Moon
Abstract:
We present results of the Near-Earth objects Lunar Impacts and Optical
TrAnsients (NELIOTA) campaign for lunar impact flashes observed with
the 1.2 m Kryoneri telescope. From August 2019 to August 2023, we
report 113 validated and 70 suspected flashes. For the validated
flashes, we calculate the physical parameters (masses, radii) of the
corresponding projectiles, the temperatures developed during the
impacts, and the expected crater sizes. For the multiframe flashes, we
present light curves and thermal evolution plots. Using the whole
sample of NELIOTA that encompasses 192 validated flashes in total from
2017, the statistics of the physical parameters of the meteoroids, the
peak temperatures of the impacts, and the expected crater sizes has
been updated. Using this large sample, empirical relations correlating
the luminous energies per photometric band were derived and used to
roughly estimate the parameters of 92 suspected flashes of the NELIOTA
archive. For a typical value of the luminous efficiency, we found that
the majority (>75%) of the impacting meteoroids have masses between 1
and 200 g, radii between 0.5 and 3 cm and produced craters up to 3.5
m. 85% of the peak temperatures of the impacts range between 2000 and
4500 K. Statistics regarding the magnitude decline and the cooling
rates of the multiframe flashes are also presented. The recalculation
of the appearance frequency of meteoroids (lying within the
aforementioned ranges of physical parameters) on the Moon yields that
the total lunar surface is bombarded with 7.4 sporadic meteoroids per
hour and up to 12.6 meteoroids per hour when the Earth-Moon system
passes through a strong meteoroid stream. By extrapolating these rates
on Earth, the respective rates for various distances from its surface
are calculated and used to estimate the probability of an impact of a
meteoroid with a hypothetical infrastructure on the Moon, or with a
satellite orbiting Earth for various impact surfaces and duration
times of the missions.
Description:
This paper presents detailed results for 113 validated and 70
suspected lunar impact flashes observed by NELIOTA between August,
2019 and mid-August, 2023. From this sample, 99 were multiframe
flashes and their light curves were presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 73 183 Photometric results and locations of the
detected flashes by NELIOTA after July 2019
tablea2.dat 144 113 Results for the validated flashes detected by
the NELIOTA campaign between August 2019 and
mid-August 2023 as well as for the corresponding
projectiles and craters for various eta values
tablea3.dat 86 92 Rough estimation of parameters of suspected LIFs
(based on the entire NELIOTA sample),
projectiles, and impact craters for
eta = 1.5x10-3
tableb1.dat 66 258 List of multiframe flashes after July, 2019
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Flash identification number
4 A1 --- n_ID [abce] Note on ID (1)
6- 28 A23 "datime" Date Observation date
30- 32 A3 --- Val Validation code (2)
34- 36 I3 ms tmax Maximum duration
38- 42 F5.2 mag Rmag Peak magnitude in R band
44- 47 F4.2 mag e_Rmag Peak magnitude in R band error
50- 54 F5.2 mag Imag ?=- Peak magnitude in I band
56- 59 F4.2 mag e_Imag ? Peak magnitude in I band error
62- 67 F6.2 deg LAT Latitude selenographic coordinate (3)
69- 73 F5.1 deg LON Longitude selenographic coordinate (3)
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Note (1): Note as follows:
a = abnormal R-I index
b = slight displacement and abnormal temperature evolution
c = too elongated shape in I filter and too short duration for its magnitude
e = ????
Note (2): Validation code as follows:
Val = Validated flash
SC1 = Suspected flash of Class 1 (see Paper III for details)
SC2 = Suspected flash of Class 2 (see Paper III for details)
Note (3): The error in the determination of the location is set as 0.5°.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Flash identification number
5- 8 A4 --- Stream Stream
10- 13 F4.1 10+4J LER Luminous energy per R band
15- 17 F3.1 10+4J e_LER Luminous energy per R band error
19- 22 F4.1 10+4J LEI Luminous energy per I band
24- 26 F3.1 10+4J e_LEI Luminous energy per I band error
28- 31 I4 K T Temperature developed during the impact
33- 36 I4 K e_T Temperature developed during the impact error
38- 42 F5.1 10+6J KEp5 eta = 5x10-3 kinetic energy
44- 46 F3.1 10+6J e_KEp5 eta = 5x10-3 kinetic energy error
48- 52 F5.1 g mp5 eta = 5x10-3 mass of the projectile
54- 57 F4.1 g e_mp5 eta = 5x10-3 mass of the projectile error
59- 61 F3.1 cm rp5 eta = 5x10-3 radius of the projectile
63- 65 F3.1 cm e_rp5 eta = 5x10-3 radius of the projectile error
67- 70 F4.2 m dc5 eta = 5x10-3 expected crater size
72- 75 F4.2 m e_dc5 eta = 5x10-3 expected crater size error
77- 79 I3 10+6J KEp1.5 eta = 1.5x10-3 kinetic energy
81- 82 I2 10+6J e_KEp1.5 eta = 1.5x10-3 kinetic energy error
84- 89 F6.1 g mp1.5 eta = 1.5x10-3 mass of the projectile
90- 94 F5.1 g e_mp1.5 eta = 1.5x10-3 mass of the projectile error
96- 99 F4.1 cm rp1.5 eta = 1.5x10-3 radius of the projectile
101-103 F3.1 cm e_rp1.5 eta = 1.5x10-3 radius of the projectile error
105-108 F4.2 m dc1.5 eta = 1.5x10-3 expected crater size
109-112 F4.2 m e_dc1.5 eta = 1.5x10-3 expected crater size error
113-116 I4 10+6J KEp0.5 eta = 5x10-4 kinetic energy
118-119 I2 10+6J e_KEp0.5 eta = 5x10-4 kinetic energy error
121-124 I4 g mp0.5 eta = 5x10-4 mass of the projectile
126-128 I3 g e_mp0.5 eta = 5x10-4 mass of the projectile error
130-132 F3.1 cm rp0.5 eta = 5x10-4 radius of the projectile
134-136 F3.1 cm e_rp0.5 eta = 5x10-4 radius of the projectile error
138-140 F3.1 m dc0.5 eta = 5x10-4 expected crater size
142-144 F3.1 m e_dc0.5 eta = 5x10-4 expected crater size error
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Flash identification number
5- 7 A3 ---- Stream Stream
9- 12 F4.1 mag Imag Peak magnitude in I band
14- 16 F3.1 mag e_Imag Peak magnitude in I band error
18- 21 F4.1 mag Rmagest Estimated peak magnitude in R band
23- 25 F3.1 mag e_Rmagest Estimated peak magnitude in R band error
27- 30 F4.1 10+4J LEI Luminous energy per I band
32- 34 F3.1 10+4J e_LEI Luminous energy per I band error
36- 39 F4.1 10+4J LERest Estimated luminous energy per R band
41- 44 F4.1 10+4J e_LERest Estimated luminous energy per R band error
46- 49 I4 K Test Estimated temperature developed during the
impact
51- 53 I3 K e_Test Estimated temperature developed during the
impact error
55- 58 F4.1 10+6J KEpest Estimated kinetic energy
60- 63 F4.1 10+6J e_KEpest Estimated kinetic energy error
65- 67 I3 g mpest Estimated mass of the projectile
69- 70 I2 g e_mpest Estimated mass of the projectile error
72- 74 F3.1 cm rpest Estimated radius of the projectile
76- 78 F3.1 cm e_rpest Estimated radius of the projectile error
80- 82 F3.1 m dcest Estimated crater size
84- 86 F3.1 m e_dcest Estimated crater size error
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Flash identification number
4- 7 A4 --- m_ID Multiplicity index on ID
9- 31 A23 "datime" Date Observation date
33- 37 F5.2 mag Rmag ?=- Estimated peak magnitude in R band
39- 42 F4.2 mag e_Rmag ? Estimated peak magnitude in R band error
45- 49 F5.2 mag Imag ?=- Estimated peak magnitude in I band
51- 54 F4.2 mag e_Imag ? Estimated peak magnitude in I band error
58- 61 I4 K T ? Temperature developed during the impact
63- 66 I4 K e_T ? Temperature developed during the impact error
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History:
From electronic version of the journal
References:
Bonanos et al., Paper I, 2018A&A...612A..76B 2018A&A...612A..76B
Xilouris et al., Paper II, 2018A&A...619A.141X 2018A&A...619A.141X
Liakos et al., Paper III, 2020A&A...633A.112L 2020A&A...633A.112L
(End) Patricia Vannier [CDS] 12-Aug-2024