We present results from 28 stellar occultations by the large Trans-Neptunian Object (50000) Quaoar registered between 2018 and 2025. By performing a joint analysis of this occultation data-set, along with other 9 published events, we were able to fit an oblate ellipsoid shape, with equatorial semi-axes, a and b of 566.1+2.5-2.2 km, and a polar semi-axis, c, of 511.2+3.6-3.7 km. It provides an equivalent volumetric diameter of 1094.4 +/- 4.6 km and polar oblateness of 0.097 +/- 0.011. Considering an absolute magnitude of H = 2.79 +/- 0.35, we derive a geometric albedo of pV = 0.125 +/- 0.038. We have derived new upper limits to the surface pressure of a CH4 atmosphere of 0.15 nbar (1-sigma) and 0.65 nbar (3-sigma). We also provide a table with the 36 new astrometric positions for Quaoar. Using the new system mass derived from Weywot's orbit around Quaoar, we calculated a density of 1.760 +/- 0.109 g/cm3. Moreover, from the derived size and rotation period (8.8394 +/- 0.0002 hours (Ortiz et al. 2003)), we calculate that, if Quaoar is in Maclaurin hydrostatic equilibrium state, it would have a density of 1.859 +/- 0.200 g/cm3. This result, within the error bars, is compatible with the value we found. Therefore, this work shows that Quaoar can be a Maclaurin object, being eligible as a dwarf planet.

This work presents a methodology for determining the size, three-dimensional shape, and rotational parameters of small solar system objects, with rigorous uncertainty determination, using stellar occultations, rotational and phase-angle light curves. Here we analyze (911) Agamemnon, considered the third-largest Jupiter Trojan, using five rotational light curves, phase-angle data, and 12 occultations (22 positive chords). The methodology uses a genetic algorithm to compare the rotational data with synthetic light curves from the 3D model, obtaining the uncertainties from the χ ^2 minimization. The model is scaled with the occultation data, to calculate dimensions, and the uncertainties. We obtained the first nonconvex model for Agamemnon using the All-Data Asteroid Modeling, considering new rotational, phase-angle, and occultation data. The methodological process was applied to derive the uncertainties, obtaining the rotational parameters λ = 128 $\mathop{.}\limits^{{\unicode{x000b0}}}$ 1 ± 0 $\mathop{.}\limits^{{\unicode{x000b0}}}$ 8, β = 2 $\mathop{.}\limits^{{\unicode{x000b0}}}$ 3 ± 2 $\mathop{.}\limits^{{\unicode{x000b0}}}$ 1, P = 6.581797 ± 0.000003 hr, and D _S = 156.0 ± 7.8 km, with a σ _model of 3 km (indicating the model quality relative to the occultation data). We also used the new data to test the 3D model provided by the Database of Asteroid Models from Inversion Techniques. From the nonconvex shape model rotated to Gaia observation epochs, we derive a geometric albedo of p _G = 0.051 ± 0.005 for Agamemnon. The final results also indicate that (911) Agamemnon may be the second-largest known Jupiter Trojan, being smaller than (624) Hektor and larger than (617) Patroclus.

In this study, we extracted two key prompt emission parameters, i.e., spectral lags and characteristic time scales, and investigated their potential correlation. The minimum variability time scale (MTS) was determined using a wavelet-based method, while spectral lag analysis was conducted via the cross-correlation function (CCF) to examine the temporal properties of 162 gamma-ray bursts (GRBs) with known redshifts observed by the Swift/BAT satellite between 2011 and 2019. The analysis suggests short-duration bursts exhibit a shorter variability time scale than long-duration bursts. Although the MTS value for most long- and short-duration GRBs is shorter than T90, a few cases approach the equality limit. Additionally, long-duration bursts tend to have a higher spectral lag than short-duration bursts. We found spectral lag values consistent with zero within their uncertainties for short-duration GRBs. Spectral lags exhibit a strong positive correlation with MTS and a negative correlation with the isotropic peak luminosity (Liso), with slopes of 1.01 ± 0.04 and -1.13 ± 0.20, respectively.

We present a comprehensive multiwavelength analysis of GRB 240825A, a bright gamma-ray burst (GRB) detected by Fermi and Swift, with a prompt duration (T_ 90 4 sec in 50-300 keV) near the boundary separating short and long GRBs, prompting a detailed investigation into its classification and progenitor. Using classical prompt metrics (duration, minimum variability timescale (MVT), lag, and spectral hardness) and modern classification techniques (machine-learning (ML) based t-SNE, support vector machine, energy-hardness-duration, and ε≡ E_γ,iso,52 / E_p,z,2^5/3), we find GRB 240825A exhibits hybrid characteristics. The short MVT (13.830 ± 1.574 ms), rest-frame duration, and ML-based classification indicate a merger-like or ambiguous nature, while its energetics and position on the Amati relation favor a collapsar origin. We conducted deep optical and NIR photometric and spectroscopic late-time search for an associated supernova (SN)/kilonova (KN) and the host galaxy using 10.4 m GTC and 8.4 m binocular LBT telescopes. No bright SN (like SN 1998bw) is detected down to stringent limits (e.g., m_r > 26.1 mag at 17.59 days), despite a redshift of z = 0.659 measured from GTC spectroscopy. Host galaxy SED modeling with Prospector indicates a massive, dusty, and star-forming galaxy-typical of collapsar GRB hosts, though with low sSFR and large offset. We compare these findings with hybrid events like GRB 211211A, GRB 230307A, GRB 200826A, including SNe-GRBs, and conclude that GRB 240825A likely originated from a massive star collapse, with the associated supernova obscured by a dusty host environment or low luminosity SN with absolute magnitude M_V fainter than -18.0. This study emphasizes the need for multiwavelength follow-up and a multi-layered classification to determine GRB progenitors.

Asteroid Justitia is a special main-belt object, being an extremely red body with a steeper spectral slope than any other D-type asteroid. Conversely, its spectral and polarimetric properties resemble organics-rich Centaurs and trans-Neptunian objects. For this reason, it was chosen as a main target of the MBR Explorer space mission. It is crucial for space mission planning and operations to have in advance the best estimate of the target size, spin, shape, and properties of the surface. In particular, the size determination was in high demand before the extensive stellar occultation campaign in 2023 August, for station deployment and observation planning. We utilized multiple lightcurves from our campaign on slow rotators and from the literature to reconstruct the spin and shape of Justitia via lightcurve inversion. Then we applied the Convex Inversion Thermophysical Model to simultaneously optimize the fit to visible lightcurves and to thermal data from infrared space observatories. We present here the pair of most precise physical models of Justitia possible before the occultation campaign, with similar properties of both solutions. The size range of Justitia was narrowed here to 55–60 km, so by a factor of 4 compared with previous estimates, and also the shape model's resolution was improved. An estimate of thermal inertia and surface roughness was also obtained, with implications for surface texture and regolith properties.

Context. Gaia18cjb is one of the Gaia-alerted eruptive young star candidates which has been experiencing a slow and strong brightening during the last 13 years, similar to some FU Orionis-type objects. Aims. The aim of this work is to derive the young stellar nature of Gaia18cjb, determine its physical and accretion properties to classify its variability. Methods. We conducted monitoring observations using multi-filter optical and near-infrared photometry, as well as near-infrared spectroscopy. We present the analysis of pre-outburst and outburst optical and infrared light curves, color-magnitude diagrams in different bands, the detection of near-IR spectral lines, and estimates of both stellar and accretion parameters during the burst. Results. The optical light curve shows an unusually long (8 years) brightening event of 5 mag in the last 13 years, before reaching a plateau indicating that the burst is still on-going, suggesting a FUor-like nature. The same outburst is less strong in the infrared light curves. The near-infrared spectra, obtained during the outburst, exhibit emission lines typical of highly accreting low-intermediate mass young stars with typical EXor features. The spectral index of Gaia18cjb SED classifies it as a Class I in the pre-burst stage and a Flat Spectrum young stellar object (YSO) during the burst. Conclusions. Gaia18cjb is an eruptive YSO which shows FUor-like photometric features (in terms of brightening amplitude and length of the burst) and EXor-like spectroscopic features and accretion rate, as V350 Cep and V1647 Ori, classified as objects in between FUors and EXors

We report results of optical identification and multi-wavelength study of a new polar-type magnetic cataclysmic variable (MCV), SRGA J213151.5+491400, discovered by Spectrum Roentgen-Gamma (SRG) observatory in the course of the all-sky survey. We present optical data from telescopes in Turkey (RTT-150 and T100 at the TÜBITAK National Observatory), and in Russia (6-m and 1-m at SAO RAS), together with the X-ray data obtained with ART-XC and eROSITA telescopes aboard SRG and the NICER observatory. We detect SRGA J213151.5+491400 in a high state in 2020 (17.9 mag) that decreases about 3 mag into a low state (21 mag) in 2021. We find only one significant period using optical photometric time series analysis which reveals the white dwarf spin/orbital period to be 0.059710(1) days (85.982 min). The long slit spectroscopy in the high state yields a power law continuum increasing towards the blue with a prominent He II line along with the Balmer line emissions with no cyclotron humps; consistent with MCV nature. Doppler Tomography confirms the polar nature revealing ballistic stream accretion along with magnetic stream during the high state. These characteristics show that the new source is a polar-type MCV. SRG ART-XC detections yield an X-ray flux of (4.0-7.0)×10^-12 erg cm^2 s^-1 in the high state. eROSITA detects a dominating hot plasma component (kT_max > 21 keV in the high state) declining to (4.0-6.0)×10^-13 erg cm^2 s^-1 in 2021 (low state). The NICER data obtained in the low state reveal a two-pole accretor showing a soft X-ray component at (6-7)σ significance with a blackbody temperature of 15-18 eV. A soft X-ray component has never been detected for a polar in the low state before.

Context. Gaia18cjb is one of the Gaia -alerted eruptive young star candidates that has been experiencing a slow and strong brightening during the last 13 years, similarly to some FU Orionis-type objects. Aims. The aim of this work is to derive the young stellar nature of Gaia18cjb and determine its physical and accretion properties to classify its variability. Methods. We conducted monitoring observations using multi-filter optical and near-infrared (NIR) photometry, as well as NIR spectroscopy. We present an analysis of pre-outburst and outburst optical and IR light curves, color-magnitude diagrams in different bands, the detection of NIR spectral lines, and estimates of both stellar and accretion parameters during the burst. Results. The optical light curve shows an unusually long (over 8 years) brightening event of 5 mag in the last 13 years, before reaching a plateau indicating that the burst is still ongoing, suggesting a FU Orionis-like (FUor-like) nature. The same outburst is less strong in the IR light curves. The NIR spectra, obtained during the outburst, exhibit emission lines typical of highly accreting low-intermediate mass young stars with typical EX Lupi-type (EXor) features. The spectral index of Gaia18cjb SED classifies it as a Class I in the pre-burst stage and a flat-spectrum young stellar object (YSO) during the burst. Conclusions. Gaia18cjb is an eruptive YSO that exhibits FUor-like photometric features (in terms of brightening amplitude and length of the burst) as well as EXor-like spectroscopic features and accretion rate. Its nature appears similar to that of V350 Cep and V1647 Ori, which have been classified as objects in between FUors and EXors.

Context. The paper is comprised of optical identification and multiwavelength studies of a new X-ray source discovered by the Spectrum Roentgen-Gamma (SRG) observatory during the ART-XC survey and its follow-up optical and X-ray observations. Aims. We aim to identify SRGA J213151.5+491400 in the optical wavelengths. We determine spectra and light curves in the optical high and low states to find periodicities in the light curves and resolve emission lines in the system using optical ground-based data. We intend to study the spectral and temporal X-ray characteristics of the new source using the SRG surveys in the high and low states and NICER data in the low state. Methods. We present optical data from telescopes in Türkiye (RTT-150 and T100 at the TÜBİTAK National Observatory) and in Russia (6-m and 1-m at SAO RAS), together with the X-ray data obtained with ART-XC and eROSITA telescopes aboard SRG and the NICER observatory. Using the optical data, we performed astrometry, photometry, spectroscopy, and power spectral analysis of the optical time series. We present optical Doppler tomography along with X-ray data analysis producing light curves and spectra. Results. We detected SRGA J213151.5+491400 in a high state in 2020 (17.9 mag) that decreased by about 3 mag into a low state (21 mag) in 2021. We find only one significant period using optical photometric time series analysis, which reveals the white dwarf spin (orbital) period to be 0.059710(1) days (85.982 min). The long slit spectroscopy in the high state yields a power-law continuum increasing towards the blue with a prominent He II line along with the Balmer line emissions with no cyclotron humps, which is consistent with a magnetic cataclysmic variable (MCV) nature. Doppler Tomography confirms the polar nature revealing ballistic stream accretion along with magnetic stream during the high state. These characteristics show that the new source is a polar-type MCV source. ART-XC detections yield an X-ray flux of (4.0−7.0) × 10−12 erg s−1 cm−2 in the high state. eROSITA detects a dominating hot plasma component (kTmax > 21 keV in the high state) declining to (4.0−6.0) × 10−13 erg s−1 cm−2 in 2021 (low state). The NICER data obtained in the low state reveal a two-pole accretor showing a soft X-ray component at (6−7)σ significance with a blackbody temperature of 15−18 eV. A soft X-ray component has never been detected for a polar in the low state before.

Context. The paper is comprised of optical identification and multiwavelength studies of a new X-ray source discovered by the Spectrum Roentgen-Gamma (SRG) observatory during the ART-XC survey and its follow-up optical and X-ray observations. Aims. We aim to identify SRGA J213151.5+491400 in the optical wavelengths. We determine spectra and light curves in the optical high and low states to find periodicities in the light curves and resolve emission lines in the system using optical ground-based data. We intend to study the spectral and temporal X-ray characteristics of the new source using the SRG surveys in the high and low states and NICER data in the low state. Methods. We present optical data from telescopes in T & uuml;rkiye (RTT-150 and T100 at the T & Uuml;B & Idot;TAK National Observatory) and in Russia (6-m and 1-m at SAO RAS), together with the X-ray data obtained with ART-XC and eROSITA telescopes aboard SRG and the NICER observatory. Using the optical data, we performed astrometry, photometry, spectroscopy, and power spectral analysis of the optical time series. We present optical Doppler tomography along with X-ray data analysis producing light curves and spectra. Results. We detected SRGA J213151.5+491400 in a high state in 2020 (17.9 mag) that decreased by about 3 mag into a low state (21 mag) in 2021. We find only one significant period using optical photometric time series analysis, which reveals the white dwarf spin (orbital) period to be 0.059710(1) days (85.982 min). The long slit spectroscopy in the high state yields a power-law continuum increasing towards the blue with a prominent He II line along with the Balmer line emissions with no cyclotron humps, which is consistent with a magnetic cataclysmic variable (MCV) nature. Doppler Tomography confirms the polar nature revealing ballistic stream accretion along with magnetic stream during the high state. These characteristics show that the new source is a polar-type MCV source. ART-XC detections yield an X-ray flux of (4.0-7.0) x 10-12 erg s-1 cm-2 in the high state. eROSITA detects a dominating hot plasma component (kTmax > 21 keV in the high state) declining to (4.0-6.0) x 10-13 erg s-1 cm-2 in 2021 (low state). The NICER data obtained in the low state reveal a two-pole accretor showing a soft X-ray component at (6-7)sigma significance with a blackbody temperature of 15-18 eV. A soft X-ray component has never been detected for a polar in the low state before.

More than 36 years have passed since the discovery of the infrared excess from circumstellar dust orbiting the white dwarf G29-38, which at 17.5 pc it is the nearest and brightest of its class. The precise morphology of the orbiting dust remains only marginally constrained by existing data, subject to model-dependent inferences, and thus fundamental questions of its dynamical origin and evolution persist. This study presents a means to constrain the geometric distribution of the emitting dust using stellar pulsations measured at optical wavelengths as a variable illumination source of the dust, which re-radiates primarily in the infrared. By combining optical photometry from the Whole Earth Telescope with 0.7-2.5 micron spectroscopy obtained with SpeX at NASA's Infrared Telescope Facility, we detect luminosity variations at all observed wavelengths, with variations at most wavelengths corresponding to the behavior of the pulsating stellar photosphere, but towards the longest wavelengths the light curves probe the corresponding time-variability of the circumstellar dust. In addition to developing methodology, we find pulsation amplitudes decrease with increasing wavelength for principal pulsation modes, yet increase beyond approximately 2 microns for nonlinear combination frequencies. We interpret these results as combination modes deriving from principal modes of identical l values and discuss the implications for the morphology of the warm dust. We also draw attention to some discrepancies between our findings and theoretical expectations for the results of the non-linearity imposed by the surface convection zone on mode--mode interactions and on the behavior of the first harmonic of the highest-amplitude pulsation mode.

X-ışın çiftlerinin taç bölgesinin doğası ve Compton saçılmasının kritik bileşeni olan düşük enerjili fotoların temelini oluşturan geometrik yapısı ile ilgili araştırmalar son yıllarda büyük ivme kazanmıştır. Bu nedenle bileşenlerinden biri Nötron Yıldız (NY) veya Kara delik (KD) olan sistemlerin özellikle düşük ışımagücü ($\lesssim10^{35}$ erg s$^{-1}$) bölgesindeki benzerlik ve farklılıklarının araştırılması oldukça önemlidir. Bu çalışmada, LMXB'lerde tayfsal indis ve X-ışın ışımagücü arasında olduğu bilinen ilişki geniş ışımagücü aralığında farklı KD (2S 0921-63, 4U 1957+11) ve NY (4U 1608-52, MAXI J1807+132) sistemleri için {\it NICER}, {\it SWIFT}, ve {\it XMM-Newton} uydu verileri kullanılarak incelenmiştir. KD ve NY sistemleri için genel olarak gözlenen ilişkinin incelenen kaynak özelliklerini uzun dönemli gözlemler için de temsil ettiği görülmüştür.

Flaring episodes in blazars represent one of the most violent processes observed in extra-galactic objects. Studies of such events shed light on the energetics of the physical processes occurring in the innermost regions of blazars, which cannot otherwise be resolved by any current instruments. In this work, we present some of the largest and most rapid flares captured in the optical band in the blazars 3C 279, OJ 49, S4 0954+658, TXS 1156+295 and PG 1553+113. The source flux was observed to increase by nearly ten times within a timescale of a few weeks. We applied several methods of time series analysis and symmetry analysis. Moreover, we also performed searches for periodicity in the light curves of 3C 279, OJ 49 and PG 1553+113 using the Lomb-Scargle method and found plausible indications of quasi-periodic oscillations (QPOs). In particular, the 33- and 22-day periods found in 3C 279, i.e. a 3:2 ratio, are intriguing. These violent events might originate from magnetohydrodynamical instabilities near the base of the jets, triggered by processes modulated by the magnetic field of the accretion disc. We present a qualitative treatment as the possible explanation for the observed large amplitude flux changes in both the source-intrinsic and source-extrinsic scenarios.

Bileşenlerinden biri Kara delik (KD) olan Düşük kütleli X-ışın çiftlerinin (LMXB'lerin), ani parlamalara uğradıklarında sergiledikleri farklı yığılma süreçleri ile ilişkili tayfsal evreler ve geçişler gösterdikleri yaygın olarak kabul edilmektedir. Kompakt bileşeni bir nötron yıldızı (NY) olan LMXB'lerin de, KD-LMXB'lere benzer tayfsal evre geçişleri sergiledikleri bilinmektedir. Bu çalışmada, parlama profili q-eğri yapısı gösteren 9 tane KD ve NY-LMXB' nin zamansal analiz sonuçları sunulmaktadır. Çalışma kapsamında RXTE arşiv verileri kullanılarak kaynakların tayfsal evreleri ile ilişkili olan minimal zaman ölçeği (MTS) elde edilmiştir. KD ve NY kaynaklarında meydana gelen tayfsal değişimleri izlemede MTS'nin öneminin ileri boyutta araştırılması için kaynakların evre geçişlerine özgü diğer parametreler olan ışıma şiddeti, RMS değişkenliği ve sertlik oranları ile karşılaştırılmıştır.

Context. As evidenced by recent survey results, the majority of asteroids are slow rotators (spin periods longer than 12 h), but lack spin and shape models because of selection bias. This bias is skewing our overall understanding of the spins, shapes, and sizes of asteroids, as well as of their other properties. Also, diameter determinations for large (>60 km) and medium-sized asteroids (between 30 and 60 km) often vary by over 30% for multiple reasons.Aims. Our long-term project is focused on a few tens of slow rotators with periods of up to 60 h. We aim to obtain their full light curves and reconstruct their spins and shapes. We also precisely scale the models, typically with an accuracy of a few percent.Methods. We used wide sets of dense light curves for spin and shape reconstructions via light-curve inversion. Precisely scaling them with thermal data was not possible here because of poor infrared datasets: large bodies tend to saturate in WISE mission detectors. Therefore, we recently also launched a special campaign among stellar occultation observers, both in order to scale these models and to verify the shape solutions, often allowing us to break the mirror pole ambiguity.Results. The presented scheme resulted in shape models for 16 slow rotators, most of them for the first time. Fitting them to chords from stellar occultation timings resolved previous inconsistencies in size determinations. For around half of the targets, this fitting also allowed us to identify a clearly preferred pole solution from the pair of two mirror pole solutions, thus removing the ambiguity inherent to light-curve inversion. We also address the influence of the uncertainty of the shape models on the derived diameters.Conclusions. Overall, our project has already provided reliable models for around 50 slow rotators. Such well-determined and scaled asteroid shapes will, for example, constitute a solid basis for precise density determinations when coupled with mass information. Spin and shape models in general continue to fill the gaps caused by various biases.

Intense outbursts in blazars are among the most extreme phenomena seen in extragalactic objects. Studying these events can offer important information about the energetic physical processes taking place within the innermost regions of blazars, which are beyond the resolution of current instruments. This work presents some of the largest and most rapid flares detected in the optical band from the sources 3C 279, OJ 49, S4 0954+658, Ton 599, and PG 1553+113, which are mostly TeV blazars. The source flux increased by nearly ten times within a few weeks, indicating the violent nature of these events. Such energetic events might originate from magnetohydrodynamical instabilities near the base of the jets, triggered by processes modulated by the magnetic field of the accretion disc. We explain the emergence of flares owing to the injection of high-energy particles by the shock wave passing along the relativistic jets. Alternatively, the flares may have also arisen due to geometrical effects related to the jets. We discuss both source-intrinsic and source-extrinsic scenarios as possible explanations for the observed large amplitude flux changes.

ABSTRACTArchival XMM–Newton, Chandra, and Hubble Space Telescope(HST) data have been used to study the X-ray and optical properties of two candidate ultraluminous X-ray sources in NGC 4536. In order to search for potential optical counterparts, relative astrometry between Chandra and HST was improved, and as a result, optical counterparts were detected for both X-ray sources. To complement our findings (based on the archival data), ground-based optical spectra of the counterparts were obtained with the 6-m BTA (Big Telescope Alt-azimuth) Telescope located at the Special Astrophysical Observatory. The calculated redshift (z = 0.4391 ± 0.0010) for one of the sources (X-3) indicates that the source is, in fact, a background active galactic nucleus. Two possible optical counterparts (s1 and s2) were found for X-2. Whether s1 is point-like or an extended source is unclear: If it is point-like and the emission is dominated by the donor, its spectral type indicates O–B star. The second source (s2) is point-like and is consistent with the colours and absolute magnitudes of a red supergiant.

In this study, we use archival data from Hubble Space Telescope (HST) , Chandra , XMM-Newton , and Swift-XRT , to probe the nature of 9 (X1-X9) candidate ultraluminous X-ray sources (ULXs) in NGC 1672. Our study focuses on using the precise source positions obtained via improved astrometry based on Chandra and HST observations to search for and identify optical counterparts for these ULXs. Unique optical counterparts are identified for X2 and X6; two potential counterparts were determined for X1, X5, and X7 within the respective error radii while no optical counterparts were found for the remaining four sources. Based on spectral energy distributions, X-ray, and optical temporal analyses, some evidences about the nature of X1 and X2 were obtained.

We present the results of our analysis of Gaia19dke, an extraordinary microlensing event in the Cygnus constellation that was first spotted by the {\gaia} satellite. This event featured a strong microlensing parallax effect, which resulted in multiple peaks in the light curve. We conducted extensive photometric, spectroscopic, and high-resolution imaging follow-up observations to determine the mass and the nature of the invisible lensing object. Using the Milky Way priors on density and velocity of lenses, we found that the dark lens is likely to be located at a distance of $D_L =(3.05^{+4.10}_{-2.42})$kpc, and has a mass of $M_L =(0.51^{+3.07}_{-0.40}) M_\odot$. Based on its low luminosity and mass, we propose that the lens in Gaia19dke event is an isolated white dwarf.

SRGA J021303.5+604536, Ocak 2021’de TUG-KFU-IKI arasındaki protokole göre paylaşılan yeni ART-XC kaynaklarından biridir. 20210313–20221019 tarihleri arasında gözlendi. Toplamda yaklaşık 1.5 yıla yayılan 17 gece boyunca bu parlak (yaklaşık 11 kadir) kaynağın RTT150 ile 127 adet tayfı alınmıştır. Kaynağın tayf sürekliliği kırmızı olduğu gibi düz özelliği de var, hidrojenin Balmer çizgileri (şiddetli H-alfa, H-beta ve zayıf H-gama), Ca II üçlüsü (8500, 8544 ve 8664 A) ve O I (8446 A) çizgileri emisyondadır. Belirgin çizgilerden bazılarının akılarını (x10E−15 erg cm−2s−1) da hesapladık: 11.04 (H-beta), 232.02 (H-alfa) ve 141.05 (O I). Kaynağın farklı teleskoplarla fotometrik verisi de alınmıştır. Sistemin yörünge periyodu yaklaşık 16 gün bulunmuştur. Verilerin değerlendirilmesi ile kaynak ilk kez simbiyotik olarak tanımlanmıştır. Sistemin tayflarında TiO absorbsiyon çizgileri görülmediğinden beyaz cüce bileşenli aktif fazda bir simbiyotik olarak değerlendirilebilir.