The stellar occultation by (319) Leona on 2023 September 13 in preparation for the occultation of Betelgeuse

ABSTRACT

On 2023 December 12, the star α Orionis will be occulted by asteroid (319) Leona. This represents an extraordinary and unique opportunity to analyse the brightness distribution of Betelgeuse’s photosphere with extreme angular resolution by studying light curves from different points on Earth and at different wavelengths. Here we present observations of another occultation by asteroid Leona, on 2023 September 13, whose goal was to determine Leona’s projected shape and size in preparation for the December 12th event and its interpretation. The occultation campaign was highly successful with 25 positive detections from 17 different sites and a near miss. The effective diameter in projected area derived from the positive detections was 66 ± 2 km using an elliptical fit to the instantaneous limb. The body is highly elongated, with dimensions of 79.6 ± 2.2 km × 54.8 ± 1.3 km in its long and short axis, respectively, at occultation time. This result, in combination with dense time series photometry of Leona that we recently obtained, together with archival sparse photometry, allowed us to predict the angular size of the asteroid for the Betelgeuse event and to simulate the expected brightness change. Also, an accurate position coming from the occultation is provided, to improve the orbit of Leona.

astrometry, occultations, minor planets, asteroids: individual: (319) Leona, stars: individual: Betelgeuse

1 INTRODUCTION

On 2023 December 12, the bright star α Orionis (Betelgeuse) will be occulted by the asteroid (319) Leona.¹ The shadow path of this event will be favourable for a thin region crossing Southern Florida and Southern Europe. Even though this naked eye event will not be observable from the entire planet, highly populated areas of the Earth will be in the path, and the potential observability of the event is considerable. Fig. 1 shows a zoomed map of the expected shadow path on Earth for the 2023 December 12 occultation of Betelgeuse using JPL|$\#$|69 orbit for Leona and a position for Betelgeuse that we have derived ourselves as explained below. Betelgeuse’s position is somewhat problematic because being such a bright optical source there is no astrometry from Gaia. On the other hand, the Hipparcos astrometric solution for Betelgeuse is old and was questioned by Harper et al. (2017) who used radio observations to derive their own and more recent solution. However, there is the possibility that the central position of the radio emission from Betelgeuse be shifted with respect to the optical emission. Recently, ground-based astrometry of bright sources became available, with an accuracy of around 4 milliarcsec (mas) by means of the USNO UBAD catalogue (Munn et al. 2022), along with derivations of proper motions and parallax in a short time span compared to other works. For Fig. 1 we use the USNO UBAD position for Betelgeuse from 2017 propagated to 2023 December with the proper motions and parallax by Harper et al. (2017). A clickable and expandable version of this map is available online.² Also, we note that this prediction assumes a spherical shape for Leona with a diameter of 61 km and it does not include the angular diameter of Betelgeuse. If we use a limb-darkening corrected angular diameter of 41.9 ± 0.06 mas for Betelgeuse (Dolan et al. 2016) we have to increase the width of the shadow path by a factor 1.9, to 116 km. All this needs to be refined for an accurate prediction and interpretation of the occultation in December. Another interactive prediction map with a different orbit for Leona and other assumptions on Betelgeuse is also available online.³

Figure 1.

Map of the central (total) occultation shadow path over Europe predicted for the 2023 December 12 occultation of Betelgeuse by asteroid Leona. Not shown is the region of partial occultation which extends in cross-track direction. JPL Horizons #69 ephemeris was used for Leona. The position of Betelgeuse was computed by using the epoch 2017.0 position from the USNO-UBAD catalogue (Munn et al. 2022) and the proper motions were taken from Harper et al. (2017). Map created using data and services from OpenStreetMap.

Asteroidal occultations of stars are frequent phenomena but the occultation of Betelgeuse by Leona will be extremely important and unique. It represents an extraordinary opportunity to analyse the diameter and brightness distribution of Betelgeuse’s photosphere by studying the light curve as the asteroid progressively occults the star from different points on Earth and at different wavelengths. In the overwhelming majority of the stellar occultations the diameters of the stars are tiny compared to the angular size of the solar system body that passes in front of them so the occultations are not gradual, but in this case, the huge angular diameter of Betelgeuse will give rise to a different phenomenon of ‘partial eclipse’ and ‘total eclipse’ (provided that Leona’s angular diameter is large enough compared with that of Betelgeuse). On the other hand, the interest in Betelgeuse has been extremely high in the last few years because of the large dimming that it experienced, which prompted all sorts of speculations and seems to be recently explained by a dusty veil (Montargès et al. 2021). Here we report results on Leona itself based on a stellar occultation on 2023 September 13, predicted and observed in preparation for the Betelgeuse event, and also present time series photometry recently obtained to determine the main rotational properties and derive the expected angular size of Leona at the time of the Betelgeuse event. Besides, the data can be used to derive a physical model of the asteroid using appropriate techniques.

2 OCCULTATION OBSERVATIONS

We predicted stellar occultations by Leona months in advance to the September event, first using ASTORB (Moskovitz et al. 2022) orbital elements for Leona together with Gaia DR3 data for the stars, and once the most promising events in terms of observability were selected, we used the Jet Propulsion Laboratory (JPL) orbit available at the time to refine the predictions. Among the very best occultations in 2023, the 2023 September 13 event clearly stood up in terms of the brightness of the star involved and the logistic capabilities as well as the potential weather in the shadow path region. Therefore, we soon started organizing its observation. For the final deployment we followed a similar procedure to the one we use for stellar occultations by trans-Neptunian objects (Ortiz et al. 2020a) and observations of Leona were obtained in an I filter to minimize differential chromatic refraction, on 3 nights prior to the occultation with the 2-m Liverpool Telescope on La Palma observatory, to try to refine Leona’s shadow path prediction. The final prediction map is shown in Fig. 2 together with the observing stations. The details of the involved star are given in Table 1.

Figure 2.

Occultation shadow path computed for the 2023 September 13 stellar occultation by Leona prior to the event. The blue lines indicate the shadow path borders, the red lines indicate the uncertainty in the path coming from the orbit, the green line indicates the centre of the shadow path, and the pins indicate the locations of the stations that participated in the campaign. The grey pins show stations that were clouded out or had weather problems, in green we show the sites that observed a positive occultation, in red the stations that recorded a negative and in brown the stations that had technical problems and could not observe. Map created using data and services from OpenStreetMap.

Table 1.

Fundamental data of the occulted star. The star position was taken from the Gaia Data Release 3 (GDR3) star catalogue (Gaia Collaboration 2023), and is propagated to the event epoch using the formalism of Butkevich & Lindegren (2014) applied with the SORA package (Gomes-Júnior et al. 2022). The duplicated source flag in GDR3 is 0, meaning that the star is not multiple or any companion would be very faint. J, H, and K magnitudes are taken from the 2MASS catalogue.

Epoch	2023-09-13 03:42:00 utc
Source ID	Gaia DR3 3 347 400 001 862 704 896
Star position	α⋆ = 05h42m12.52922s ± 0.16 mas
at epoch	δ⋆ = 14°00′04.10756″± 0.10 mas
Magnitudes	G = 11.89, J = 10.34, H = 10.57, K = 10.23
Apparent diameter	0.02 mas (0.21 km on the sky plane)

The occultation observation campaign was highly successful. In total, 23 observing stations participated in the campaign, 9 of which were specifically deployed for the event. All the participating stations are listed in Supplementary table 1 together with their instruments and setups used. Note that at Los Coloraos, three different telescopes detected the event and the three of them are listed in the table. At Calar Alto, seven identical telescopes detected the occultation but only one entry for them (M5) is given in the table. Therefore, 25 telescopes detected the event but from 17 different locations.

3 OCCULTATION ANALYSIS AND RESULTS

The image sequences or the video files, compiled and managed through the Tubitak Occultation Portal website (Kilic et al. 2022), were dark-current subtracted and flatfielded whenever these calibration files were available. Bias frames were not separately subtracted as the bias contribution was already in the dark frames that we subtracted. Aperture photometry of the target star (blended with Leona) from the image sequences or video was carried out using different synthetic apertures to get the least dispersion possible in the relative photometry. Comparison stars of similar brightness were also measured to derive the relative photometry to compensate for small atmospheric fluctuations. The methods used were the same as those described in Ortiz et al. (2020a). For a quick and uniform output of all the observations we used the occultation-oriented photometry software packages tangra⁴ and pymovie.⁵ A sample light curve is shown in Fig. 3.

Figure 3.

Occultation light curve derived from the observations carried out at Cortijo Veneroso.

The positive light curves show clear brightness drops from which time of ingress and time of egress at each site was derived. This was done through square well fits to the occultation profiles as usually done in occultation work (e.g. Ortiz et al. 2020b; Morgado et al. 2023). For a fast and uniform derivation of the ingress and egress times we used the asteroidal occultation time analyser (aota)⁶ and python occultation timing extractor (pyote)⁷ software packages. The ingress and egress times for all the sites are listed in Supplementary table 2. Due to the urgency to report results, conservative errors were used for the ingress and egress times. Three of the stations (Calar Alto, Albox, and University of Jaen) had gaps (deadtime) in the image acquisition sequence. In these cases we used half the deadtime as the uncertainty to be on a safe side. One of the stations with gaps in the acquisition was at the Calar Alto observatory, but given that we used seven 0.4-m telescopes there, two of the telescopes captured the ingress during the integration time so the ingress time could be determined accurately.

One of the stations recorded the occultation from a trailed image using the drift-scan technique. In this case the ingress and egress times were derived with scanalyzer⁸ software, which is specific for this type of observations.

Besides, for those instruments using NTP as the time synchronization tool for the acquisition computers we included an additional 0.1s uncertainty which we added quadratically for the analysis in the next section. Three stations (University of Jaen, Huelma, and Jodar) did not have their computers properly synchronized through NTP due to problems in the configuration. The resulting chords from these stations deviated somewhat from nearby chords so we applied small offsets of a few tenths of seconds to align with the nearby chords. These stations were not used for the elliptical fit shown in the next section.

To determine the projected shape of Leona during the occultation we first used the set of measurements that were obtained with GPS time insertion to make sure we do not have effects due to timing issues, and also used the negative occultation north of the body together with the grazing occultation at Calar Alto observatory, near the south part of the body. From these, we obtained the chords and the least-squares elliptical fit shown in Fig. 4. The dimensions are 78.2 ± 2.5 km × 54.0 ± 1.3 km with a position angle of 55 ± 5 degrees for the major axis of the ellipse. We note that the rms of the fit is 2.3 km, meaning that an ellipsoidal shape is an overall rough approximation for Leona’s shape as the residuals are slightly above those expected from the accuracy in the ingress and egress timing of the GPS-based chords. We note that even though the Huelma chord was obtained with a GPS-based camera, the GPS did not get a lock so NTP sync was finally used and this station was not included in the initial fit.

Figure 4.

Chords of the stellar occultation and an elliptical fit to the extremities, projected on the sky plane. The ingress uncertainties are shown with pink color at the leftmost extremities of each chord and the egress uncertainties are shown with clear brown at the rightmost extremities. The values in parenthesis are the chords lengths. The scale is in km. The dashed line indicates the negative obtained from the Úbeda location. The chords were built using the JPL|$\#$|69 ephemeris.

Then, we incorporated the rest of the chords and performed another fit, which changed the results of the fitted ellipse very slightly, within the error bars. The dimensions are 79.6 ± 2.2 km and 54.8 ± 1.3 km with a position angle of 50.6 ± 3.5 degrees for the long axis of the ellipse. The rms of the fit was 2.6 km, also very similar to the fit of the GPS-based chords. From visual inspection there appears to be deformations of the body with respect to an ellipsoidal shape. From the fit, the centre of the body was off with respect to the JPL|$\#$|69 ephemeris by −19.9 ± 0.6 km and +1.5 ± 0.8  km in RA·cos(Dec) and Declination, respectively, or −10.2 ± 0.3 mas and 0.8 ± 0.4 mas. From the fit, we obtained a geocentric position of Leona at date and time 2023 September 13 03:46:29.440 ut as RA = 05h42m12.54493s ± 0.4 mas, Dec = 14°00′05.1461″ ± 0.5 mas.

The equivalent diameter to that of a sphere from the elliptical fit is 66 ± 2 km. This is considerably larger than the effective thermal diameter of 49.943 ± 0.477 km reported in the WISE/NEOWISE catalogue (Masiero et al. 2014) while very close to the 65.90 ± 0.92 km from AKARI measurements reported in a previous paper by Usui et al. (2011). Our determination is also consistent with the much coarser thermal diameter estimate of 89.00 ± 27.92 from the NEOWISE reactivation mission as reported in Nugent et al. (2016).

In its longest dimension Leona is considerably larger than the nominal 61 km value that was adopted here to make the prediction maps. This axis, projected in the direction perpendicular to the chord will be 60 km on 12 December, corresponding to 46 mas. This could mean that the Betelgeuse occultation would be total if Betelgeuse’s diameter is 41.9 mas but in the small dimension of Leona, the 54 km translate into 41 mas on December 12, just very near the limit to produce totality. But given that the projected area of Leona changes with rotation, we need to know the rotation state of Leona and for that reason we obtained time series photometric observations of Leona.

4 TIME SERIES PHOTOMETRY OF LEONA

4.1 Teide two-metre twin telescope observations

Photometric data were obtained between 2023 September 18 and October 15 with the Two-Meter Twin Telescopes (TTT) facility. It is located at the Teide Observatory, on the island of Tenerife (Canary Islands, Spain), and currently has its first two telescopes, TTT1 and TTT2, undergoing their final commissioning phase. These two telescopes have an aperture of 0.80-m, altazimuth mount and two Nasmyth foci with focal ratio f/6.8 and f/4.4. In the fastest port, a QHY411M camera, with a sCMOS sensor of 3.76 μm pixel⁻¹ and 151 megapixels, is installed (Alarcon et al. 2023). The full-frame FoV is 52.3 arcmin × 39.2 arcmin and the plate scale is 0.221 arcsec pixel⁻¹. A SDSS g′ filter was used in all the observations made with these telescopes.

Data reduction was done using standard procedures. The images were bias and sky flat-field corrected. Then, an average 2 × 2 binning was applied and a central region of 18.4 arcmin × 18.4 arcmin was cropped. Aperture photometry was performed using tycho tracker⁹ software (Parrott 2020). The images were aligned with bicubic interpolation and downsampled by a factor 2 for astrometric calibration, performed with Astrometry.net (Lang et al. 2010). A fixed circular aperture of 2×FWHM in the first image was used. An outer ring located at 4×FWHM was used to estimate the sky background signal. The same apertures were used for the comparison stars, selected constraining 0.60 < (B − V) < 0.70. The initial and final positions of the track were marked manually to prevent uncertainties in the object position coming from the ephemerides.

4.2 TRAPPIST north and south observations

Photometric observations of Leona were obtained from 2023 September 17 till 2023 October 8 with one or both of the TRAPPIST telescopes in order to sample Leona’s rotation curve each night. We used TRAPPIST-South (TS) located at the ESO La Silla Observatory in Chile (Jehin et al. 2011), and TRAPPIST-North (TN) located at the Oukaïmeden observatory in Morocco. They are 0.6-m Ritchey-Chrétien telescopes operating at f/8. The camera on TS is a FLI ProLine 3041-BB CCD camera with a 22 arcmin field of view and a pixel scale of 0.64 arcsec pixel⁻¹. TN is equipped with an Andor IKONL BEX2 DD camera providing a 20 arcmin field of view and pixel scale of 0.60 arcsec pixel⁻¹. We used the blue-cutting Exo filters, no binning, and exposure times of 120 s. The photometry was obtained with the Photometry Pipeline (Mommert 2017) and the magnitudes were calibrated to the Rc Johnson-Cousins band with the PanSTARRS DR1 catalogue using typically 100 field stars with solar-like colours in each image.

4.3 ATLAS observations

The ATLAS survey data for Leona were retrieved from the Minor Planet Center (MPC)¹⁰ using the set of Leona observations in the MPC catalogue but selecting only measurements reported from the ATLAS observatories. The sparse ATLAS observations in the c filter were scaled to the o filter values by a factor obtained by taking the median of the observations in the separated filters and looking for the magnitude offset needed. The TRAPPIST observations were scaled to the ATLAS o filter by doing the same procedure. The ATLAS data consisted mostly of few observations per night typically separated by one or a few nights. We retrieved data since 2019 to 2023 October 5.

5 PHOTOMETRY ANALYSIS AND RESULTS

All the ATLAS data since 2019 were corrected for heliocentric and geocentric distance, to derive a reduced magnitude at 1 au from Earth and the Sun, and the values were plotted versus phase angle from which an absolute magnitude and phase slope were derived. The phase angle dependence was very well fitted with a linear trend and the magnitudes corrected for this linear trend. The TRAPPIST and TTT data were corrected for heliocentric and geocentric distance and the same phase slope parameter as for ATLAS was used. The Teide observations were typically obtained in runs of  2–3 h, the maximum time that Leona was observable from the site. The TRAPPIST observations were also typically executed in 2–3 h runs. However, the ATLAS data are very sparse. Here we combined the dense TRAPPIST plus the TTT data with the sparse data from ATLAS.

We separated the data in different groups. First, we analysed the group of data for the current apparition of Leona, which spans around 80 d and is the densest set of photometry measurements. We did this because we need to make sure that the geometric orientation of the spin axis with respect to the observer does not change significantly. A periodogram analysis clearly indicated that the data could not be reproduced with just a rotation, in agreement with the conclusions of Pilcher, Franco & Pravec (2017) who required a slow rotation and a precession to explain their 2016 data. In Fig. 5 we show a zoomed part of our data set.

Figure 5.

Combined photometry of Leona from ATLAS (diamonds), TRAPPIST (red dots), Teide TTT (green dots), 2-m Liverpool LT (triangles) and Calar Alto (plus symbols) and Albox data taken right after the occultation observations (square symbol). We show only the latest data.

We used equation (6) of Pravec et al. (2005) to look for the rotation and precession periods of Leona in our preferred data set. Our best fit is obtained for a spin period of 321 h and a precession period of 766 h. The resulting fit is shown in Fig. 6. With plus symbols we show the predicted flux during the September occultation and at the future Betelgeuse event. Our best fit gives a similar rotation period to that preliminary obtained in an online report by Durech et al. (2023), but the precession period is longer in Durech et al. (2023) who analysed sparse data of Leona from ATLAS, Gaia DR3, and from Pilcher, Franco & Pravec (2017). We tried to fit our data with the 314 h and 1172 h periods preliminary obtained in Durech et al. (2023), but the result was significantly poorer than with our fit and could not reproduce the densest part of the ATLAS data in 2023 September. However, a solution with rotation period of 321h and a precession of 1202h, which is close to the solution by Durech et al. (2023) produced a fit as good as our nominal best fit.

Figure 6.

Group of data of the latest Leona apparition that we have used to look for a rotation and a precession period (purple dots), translated into linear flux instead of magnitudes, together with a fit (blue line) to equation (6) of Pravec et al. (2005). The average residuals of the fit to the TRAPPIST and TTT data are 0.019 and 0.078 for the ATLAS data. The green plus symbols mark the September 13 and December 12 occultation events. The flux at the December 12 event from the fit is 0.981 whereas the fit on September 13 is 0.945, which means that the projected area on December 12 is expected to be slightly larger than on September 13 by 3.8 per cent.

A rotation of 430 h and a precession of 1084 h as reported in Pilcher, Franco & Pravec (2017) provided an acceptable fit to the data, but again, it was poorer and it did not reproduce all the light-curve features, especially in the densest part of the data, which are also the best in terms of photometry accuracy. Besides, the expected flux of Leona at the September occultation and in all cases except for our best fit, is well below the average flux, which would mean that the Leona equivalent diameter presented during the occultation is even smaller than the rotationally average equivalent diameter. Given that our occultation-date diameter is already larger than most of the diameter estimations of Leona, an even larger value is not likely. Hence this is an additional hint to prefer the period of 321 h and the precession near 766 h. Nevertheless a rotation period of 429.9 h and a precession of 1104 h, close to the Pilcher, Franco & Pravec (2017) solution, gives a good fit to our data.

We also analysed a group of ATLAS data in the apparition previous to the current one. We found that a period of 316 h and a precession of 1365 h, which are again similar values to those preliminary obtained by Durech et al. (2023) can fit the ATLAS data of 2022 although the reduced χ² is considerably poorer than our first group fit. Given the very sparse sampling in the ATLAS and Gaia data, which was also the case in the Pilcher, Franco & Pravec (2017) data, mainly based on 15-min measurements on consecutive days, it seems possible that some information is being missed in comparison with our first group of data, which includes dense photometry.

6 DISCUSSION

To make an accurate prediction for the Betelgeuse event we need to know the instantaneous equivalent diameter on December 12, which depends on the rotation of Leona. Therefore, accurate knowledge of the rotational state of Leona on September 13 is required to use the occultation results appropriately.

Behrend et al. (2023) reports a 2.16 d rotation period with a light-curve amplitude of about 0.5 mag.¹¹ However, from 2016 (August–December) photometry, Pilcher, Franco & Pravec (2017) obtained two long period solutions (430 ± 2 and 1084 ± 10 h), one of which could indicate tumbling. They observed a ∼0.7 mag light-curve amplitude.

With our best light-curve data fit combined with an equivalent diameter of 66 km we have obtained for the September 13 occultation (Section 3), the predicted equivalent diameter of Leona for the Betelgeuse event is 67 ± 2 km. This is similar to the projected area of the expected silhouette of Leona at the time of the Betelgeuse event shown in Durech et al. (2023). Our fit translates into 53 mas for the angular diameter on December 12. If we use the other different fits, we still get a very similar effective diameter of Leona for December 12th.

This would mean that the occultation of Betelgeuse would be total given the angular diameter of Betelgeuse of 41.9 mas used here, but note that in its shorter axis Leona will subtend slightly more than 41 mas, meaning a very brief totality. Also, regarding the angular diameter of Betelgeuse, we note that this depends on wavelength and on numerous aspects as discussed in e.g. Dolan et al. (2016). Hence, observations of the Betelgeuse occultation at different wavelengths are encouraged even for observers somewhat outside the nominal shadow path to look for very faint extinction drops. Note the magnitude drop can be as high as ∼14 mag and in order to observe the occultation with enough SNR at different phases in just a few seconds very careful planning is needed. Also, note that common detectors rarely have the large dynamic range needed to accommodate such a large ∼14 mag drop. We have built an online simulator¹² of the Betelgeuse occultation with a selectable angular diameter of Betelgeuse and other input parameters that can be modified starting from the mean values used here as default parameters. Also, updates to the photometry will be available. This should be useful for planning and quick analysis of the data.

7 CONCLUSIONS

We successfully observed a stellar occultation by Leona on 2023 September 13. A large number of chords (17) on the body were obtained and a near miss to the north was also recorded, obtaining an excellent body coverage. This allowed us to derive accurate dimensions for Leona and an approximate silhouette. From an elliptical fit to the instantaneous limb the dimensions are 79.6 ± 2.2 km × 54.8 ± 1.3 km. Small deviations from an ellipsoidal shape are observable in the limb with rms of 2.6 km. The equivalent diameter to that of a sphere in area sense is 66 ± 2 km, somewhat larger than the previous expectations. From our own photometry and archival photometry of Leona in the current apparition, we presented the best fit to the data, and determined that the effective diameter of Leona at the time of the Betelgeuse occultation will be 67 ± 2 km, which translates into 53 ± 1.5 mas. Also, an accurate position for the centre of the body has been obtained with an uncertainty below the 1 milliarcsec level from which the orbit of Leona can be improved in preparation for the December Betelgeuse event.

ACKNOWLEDGEMENTS

Part of this work was supported by the Spanish projects PID2020-112789GB-I00 from AEI and Proyecto de Excelencia de la Junta de Andalucía PY20-01309. Financial support from the grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033 is also acknowledged. MS-G acknowledges the financial support from the Planetary Society via its ‘2023 Gene Shoemaker NEO Grant’. JM and PLLE are supported by grant PID2019-105510GB-C32/AEI/10.13039/501100011033 from the State Agency for Research of the Spanish Ministry of Science and Innovation. They also acknowledge support by Consejería de Economía, Innovación, Ciencia y Empleo of Junta de Andalucía as research group FQM- 322, as well as FEDER funds. PS-S acknowledges financial support from the Spanish I+D + i project PID2022-139555NB-I00 funded by MCIN/AEI/10.13039/501100011033. JLR acknowledges financial support by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR. We thank M. Pugnaire for observing support at Los Coloraos observatory. AR and SA acknowledge the financial support through the Europlanet Society Public Engagement Funding Scheme 2023, sponsored by the ‘Dill Faulkes Educational Trust’. This article is partly based on observations made in the Observatorios de Canarias of IAC with the Liverpool Telescope operated on the island of La Palma by the Liverpool JMU in the Observatorio del Roque de los Muchachos. This article includes observations made in the Two-metre Twin Telescope (TTT) in the Teide Observatory of the IAC, that Light Bridges operates in the Island of Tenerife, Canary Islands (Spain). The Observing Time Rights (DTO) used for this research were provided by IAC. This article includes observations made with TRAPPIST telescopes. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liége, in collaboration with the Cadi Ayyad University of Marrakech (Morocco). EJ is a F.R.S.-FNRS Senior Research Associate. FLR thanks the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo) granted by CNPq grant number 465376/2014-2. PJG acknowledges financial support from project PID2021-126365NB-C21 (MCI/AEI/FEDER, UE).

DATA AVAILABILITY

The data underlying this article will be shared on reasonable request to the corresponding author.

Footnotes

1

This event was probably first found and announced by D. Denissenko in 2004: https://web.archive.org/web/20121216061951/http://hea.iki.rssi.ru:80/~denis/special.html

2

https://astro.kretlow.de/cora/occultations/aa3579fb-2fa7-4a89-8452-bfc8a87e0704/

3

https://lesia.obspm.fr/lucky-star/occ.php?p = 124370

4

http://www.hristopavlov.net/Tangra/Tangra.html

5

https://pypi.org/project/pymovie/

6

http://www.lunar-occultations.com/iota/occult4.htm

7

https://pypi.org/project/pyote/

8

http://www.asteroidoccultation.com/observations/DriftScan/Scanalyzer.zip

9

https://www.tycho-tracker.com

10

https://minorplanetcenter.net

11

https://obswww.unige.ch/~behrend/r000319-01a.png

12

https://starblink.org/occult_simulator_en