Three leading models have been put forth to justify the observed radio re-brightening associated with stripped-envelope supernovae (SESNe) years post-explosion: radiation from an emerging pulsar wind nebula (PWN), shock interaction with a dense circumstellar medium (CSM), or emission from off-axis, relativistic jets. SN 2012au is a particularly intriguing SESN in this regard, as observations obtained greater than or similar to 6 yr post-explosion have shown both (i) optical emission features consistent with a young PWN and (ii) a radio re-brightening. We present the results of our very long baseline interferometric (VLBI) observations of SN 2012au performed between 8 and 13 yr post core-collapse. Our VLBI observations reveal a luminous, steadily fading radio source that remains compact (<= 1.4 & times; 1017 cm) and stationary (<= 0.36c) over the course of our campaign. Overall, we find that our VLBI measurements can be readily explained by a similar to decade-old PWN, potentially explained by shock interaction with specific CSM geometries, and are unlikely to be explained by emission from an off-axis, relativistic jet. Assuming a PWN origin, our observations require that the initial spindown luminosity of the central pulsar be between 1036ergs-1 <= E0 <= 4 & times;1042ergs-1 and radio efficiency factor be eta R >= 3 & times; 10-7 (both quoted at the 99.7% confidence interval). These results are consistent with independent inferences obtained using optical spectroscopy of SN 2012au, alongside inferences of known Galactic systems. If a PWN origin is confirmed, SN 2012au would represent the first extragalactic PWN emerging from a modern-day SN, providing a novel opportunity to study the formation properties of a decade-old pulsar.

Rapid localisation and follow-up of gamma-ray bursts (GRBs) increasingly rely on low-latency triggers from new missions coupled to wide-field robotic optical facilities. We present the discovery and multi-wavelength follow-up of GRB 250818B, detected by the Space Variable Objects Monitor (SVOM) and localised optically by the Gravitational-wave Optical Transient Observer (GOTO). We compile and homogenise X-ray, optical/NIR, and radio data to build broadband light curves and spectral energy distributions. The afterglow is unusually luminous for a nominal short GRB, lying on the bright end of the short-GRB population in X-rays and optical and among the most luminous high-redshift short-GRB afterglows in the radio. MeerKAT detects the source at 3.1 GHz, while ALMA provides deep higher-frequency limits. Keck/LRIS spectroscopy shows continuum and metal absorption (Fe II, Mg II, Mg I), giving z=1.216. Synchrotron forward-shock modelling favours a constant-density medium and strongly prefers refreshed (energy-injection) emission, well described by a two-component jet with E_K,iso∼ 4×10^52 erg, n_0 ∼ 3.6 cm^-3, θ_j ≃ 0.10 rad (∼ 5.7 deg), and p ≃ 1.64. The host association is ambiguous: the nearest LS DR10 galaxy candidate (r_AB∼ 24.7) is offset by ∼ 4 arcsec (∼ 34 kpc) with chance-alignment probability P_cc∼ 0.2, and current imaging does not exclude a fainter, near-coincident host. SED fitting of the candidate host suggests a low-mass galaxy. GRB 250818B highlights the power of rapid wide-field counterpart identification in the SVOM era, while host-association uncertainty can still limit offset-based interpretation.

Recent observations presented in Y. Cendes et al. show that optically selected tidal disruption events (TDEs) commonly produce delayed radio emission that can peak years after disruption. Here, we explore the multiwavelength properties of a sample of radio-observed optically selected TDEs, to shed light on the physical process(es) responsible for the late-rising radio emission. We combine new late-time X-ray observations with archival optical, UV, X-ray, and radio data to conclude that a diversity of accretion-driven outflows may power the delayed radio emission in TDEs. Our analysis suggests that some late radio outflows may be launched by a delayed phase of super-Eddington accretion onto the central supermassive black hole (SMBH), while others may result from a state transition to a "low-hard" radiatively inefficient accretion flow or the deceleration of an off-axis relativistic jet. We find that TDEs with delayed radio emission are less likely to exhibit helium emission lines at early times (p = 0.002) and may have larger optical/UV photospheric radii (p = 0.026) than other TDEs, possibly also indicating that the onset of SMBH accretion is delayed in these systems. Our results have implications for our understanding of state changes in SMBH accretion flows, the circularization timescale for TDE debris, and the prevalence of off-axis jets in TDEs, and they motivate systematic long-term monitoring of these unique transients. The objects in our sample with the brightest radio emission are also detected in the Very Large Array Sky Survey, demonstrating that all-sky radio surveys can play an important role in discovering unexpected properties of the TDE population.

Multiwavelength analyses of astrophysical transients are essential for understanding the physics of these events. To make such analyses more efficient and effective, we present the Open mulTiwavelength Transient Event Repository (OTTER), a publicly available catalog of published transient event metadata and photometry. Unlike previous efforts, our data schema is optimized for the storage of multiwavelength photometric datasets spanning the entire electromagnetic spectrum from multiple published sources. Open-source software, including an application programming interface (API) and web application, are available for viewing, accessing, and analyzing the dataset. For the initial release of OTTER, we present the largest ever photometric archive of tidal disruption event (TDE) candidates, including greater than or similar to 118,000 observations of 240 TDE candidates spanning from radio to X-ray wavelengths. We demonstrate the power of this infrastructure through four example analyses of the TDE population. We plan to maintain this dataset as more TDE candidates are proposed in the future and encourage other users to contribute by uploading newly published data via our web application. The infrastructure was built with the goal of archiving additional transient data (supernovae, gamma-ray bursts, fast blue optical transients, fast radio bursts, etc.) in the future. The web application is available at https://otter.idies.jhu.edu and the API documentation is available at https://astro-otter.readthedocs.io.

We report the detection of linear polarization in the radio afterglow of GRB 260310A, representing the first centimeter-wavelength polarization detection of a gamma-ray burst (GRB) afterglow and the first measurement of Faraday rotation in a GRB environment. We detect linearly polarized emission across 11–25 GHz, with a polarization fraction decreasing monotonically from (3.18 ± 0.18)% at 25 GHz to (0.69 ± 0.22)% at 11 GHz. We model the multiwavelength data as emission from a refreshed forward shock (FS) that dominates in the optical and X-rays and a reverse shock (RS) in a structured, relativistic jet that dominates at radio wavelengths. The observed depolarization toward the lower radio frequencies is consistent with suppression by RS synchrotron self-absorption, while the low observed polarization at high frequencies relative to the theoretical maximum suggests a patchy magnetic field in the jet with a coherence scale, θ _B ≈ 10 ^−2 rad. We identify a frequency-dependent rotation of the polarization angle consistent with Faraday rotation, with a rotation measure (RM) of RM = −(8300 ± 90) rad m ^−2 at the GRB redshift. The magnitude of the RM is consistent with propagation through a dense, magnetized environment, such as a progenitor H II region. These findings demonstrate that GRB afterglows exhibit measurable linear polarization at centimeter wavelengths, and that their polarimetric properties probe both intrinsic jet magnetization and the surrounding medium. Future multifrequency polarimetric monitoring over timescales of days to weeks will enable detailed studies of the evolution of magnetic field structure and provide new constraints on the role of magnetic fields in GRB afterglows.

We present a detailed radio study of the tidal disruption events (TDEs) AT 2020zso and AT 2021sdu. Both exhibit transient radio emission beginning shortly after optical discovery and persisting for several years. For AT 2020zso, we identify two distinct radio flares. The first is detected in the radio similar to 22 days after the optical peak, reaching a maximum of similar to 1 yr post-discovery before fading. The second flare appears similar to 800 days after discovery and results in the brief presence of two distinct components in the radio spectra, providing strong evidence for physically separate outflows. Both flares are consistent with nonrelativistic outflows, with velocities of v approximate to 0.1-0.2c and energies of E similar to 1049 erg, propagating through a Bondi-like circumnuclear medium. Our analysis supports a scenario in which the first outflow is accretion driven, launched while the TDE disk is accreting at a relatively high Eddington fraction, whereas the second outflow is associated with a transition to an advection-dominated accretion flow. In contrast, the radio emission from AT 2021sdu is best explained by a slower (v approximate to 0.03c), less energetic outflow (E similar to 1048 erg), combined with diffuse, nonvariable host emission that becomes dominant similar to 500 days after discovery. Assuming free expansion, we infer an outflow launch date preceding the optical discovery date. This suggests that the outflow may originate from either the unbound stellar debris ejected during disruption or, alternatively, from a decelerating outflow. Our findings demonstrate the diversity of outflow properties in TDEs and highlight the observational challenges of interpreting late-time radio variability in the presence of host galaxy contamination.

We present multi-epoch, multi-frequency radio observations of the tidal disruption event (TDE) AT 2022wtn, obtained with the Karl G. Jansky Very Large Array (VLA) and Giant Metrewave Radio Telescope (GMRT), spanning 97-866 days after optical detection. The peak radio flux density increases until 300 days post optical discovery, flattens out for several hundred days, then begins to decrease at 534 days. Utilizing an updated equipartition analysis framework, we estimate several physical parameters of the event and the surrounding medium. We model AT 2022wtn with two different geometries: a spherical and a conical emitting region. The spherical outflow model gives an expansion velocity of v≈0.21c and a kinetic energy of ∼3.8×10^49 erg, and the conical outflow model yields a higher energy (∼1.8×10^50) and velocity (v≈0.41c) than the spherical case. After ruling out the possibility of a relativistic jet, we consider several potential origins for sub-relativistic outflow regions in TDEs including unbound debris streams, collisionally-induced outflows, an accretion-driven wind, and an outflow from an accretion disk state transition, and find only an accretion disk state transition outflow to be consistent with the high energy and velocity found in our equipartition results. AT 2022wtn is a uniquely powerful non-relativistic radio-emitting TDE, and joins a growing population that display a diverse range of outflow properties.

We present JWST/NIRCam observations of the extremely long-duration gamma-ray burst (GRB) 250702B taken at 95 days post-GRB (observer frame). The observations of the host galaxy reveal a single galaxy with a prominent dust lane observed nearly edge-on. Prospector modeling of the host galaxy photometry finds a high stellar mass (log(M_*/M_Sun) = 11.0 +0.2/-0.3) and large dust column (A_V = 2.8 +/- 0.3 mag), in agreement with previous results. If GRB 250702B is a collapsar-driven GRB, the host galaxy is the brightest (in rest-frame r and rest-frame H) and most massive compared to GRB hosts at similar redshifts. The transient localization is near the dust lane, and while we find no evidence for transient emission in F277W, F356W, and F444W, forced photometry in F150W and F200W reveals possible 3 sigma detections of the transient at m_F150W 27.9 AB mag and m_F200W 27.4 AB mag. If these are secure detections, they are indicative of a late-time light curve flattening. This behavior is consistent with that of jetted tidal disruption events (TDEs); however, it is also consistent with a supernova plus GRB afterglow model. Alternatively, if these are upper limits, they are consistent with, but do not further constrain, the extrapolated power-law decline of the afterglow. The ambiguity of the possible detection of the transient in F150W and F200W highlights the need for late-time template observations with JWST/NIRCam.

In addition to a gamma-ray burst (GRB), the merger of two neutron stars (NSs) may produce a temporarily or indefinitely stable NS remnant with a strong magnetic field (a “magnetar”). As this magnetar remnant spins down, it can deposit its rotational energy into the surrounding kilonova ejecta, producing synchrotron emission that peaks in the radio bands ∼months to years after the merger (“boosted kilonova”). The nearby ( z = 0.0763) long-duration GRB 211211A, which has an apparent kilonova counterpart and likely NS merger progenitor, may have produced such a remnant. We observed the location of GRB 211211A at 6 GHz with the NSF’s Karl G. Jansky Very Large Array (VLA) spanning ≈0.54–1.7 yr after the burst. We do not detect any radio emission, placing strong limits on the energy deposited into the ejecta by any remnant to ≲4.4 × 10 ^52 erg. Due to the proximity of the event, we are also able to place limits on a kilonova afterglow that did not receive any additional energy deposition, though it is possible such emission will be suppressed until ∼4 yr after the burst, when the kilonova is expected to overtake the forward shock of the GRB. Future observations with the VLA and next-generation radio facilities will be able to further constrain the magnetar-boosted kilonova and kilonova-afterglow scenarios, as well as directly constrain models in the scenario that GRB 211211A was instead produced by a collapsar.

We present the results from an extensive broad-band (radio to X-rays) observing campaign of the engine-driven Type Ib SN 2012au in the first 13 years of evolution. The early-time (δt≤190 d) radio and X-ray evolution is well-described by conventional models of a forward shock interacting with a wind-like circumstellar medium (ρ_CSM∝r^-2). However, starting at δt≈6.7 yr, we detect a significant radio re-brightening. This late-time emission is dominated by a luminous component characterized by a broad and rapidly evolving spectral peak and a shallow optically thin spectral slope, F_ν^-0.31±0.02. These properties imply a compact emitting region (R≲10^16 cm) expanding at a remarkably slow velocity (≲500 km/s) into a high-density environment (≥10^4 cm^-3), accompanied by a hard electron power-law index p≈1.6. No soft or hard X-ray emission is detected at any epoch, indicating that high-energy radiation is either strongly absorbed or intrinsically absent. In the context of aspherical shock-CSM interaction models, these observations imply extreme properties of the CSM (geometry, density, total mass) that lack clear astrophysical motivation. Instead, we show that the emergence of radiation from a newborn Pulsar Wind Nebula (PWN) naturally explains the radio spectral evolution and high-energy limits, where the emission is governed by the adiabatic expansion of a relic pair plasma. We conclude that SN 2012au represents the most compelling candidate for a young, newborn PWN discovered to date, a scenario that can be directly tested with pending Very Long Baseline Interferometry (VLBI) observations.

We report new radio observations of the tidal disruption event (TDE) AT 2023mfm, which we identified as a high-confidence candidate in a systematic search for off-nuclear TDEs. High-resolution NSF Karl G. Jansky Very Large Array C-band (6 GHz) imaging resolves two radio sources: one consistent with the host-galaxy nucleus and one offset by 0.651±0.036^'' (1.06±0.06 kpc), consistent with the Zwicky Transient Facility and Pan-STARRS1 positions of AT 2023mfm. These observations confirm the off-nuclear nature of AT 2023mfm, demonstrating the power of high-resolution radio imaging to validate off-nuclear TDE candidates and reveal hidden off-nuclear massive black holes.

We present an extensive radio monitoring campaign of the unique extragalactic transient GRB 250702B, with observations spanning 0.65-233 GHz from 6-356 d (observer frame) post-discovery. The radio emission shows a smoothly evolving peaked synchrotron spectrum consistent with an adiabatic shock expanding into a stratified ambient medium (n_e∝ R^-k; k= 1.5-2). We detect significant variability in the low frequency (≤3 GHz) light curves which we interpret as interstellar scintillation, placing an approximate bound on the blast wave image size of 1.2×10^16≲ R_⊥≲ 5×10^17 cm. The temporal evolution of the flux density and critical synchrotron frequencies suggest the shock that powers the radio emission is potentially a wide-angle θ_j≳15 deg, low Lorentz factor (Γ≲10) jet, or a narrow θ_j≲2 deg highly relativistic jet. A narrow jet is expected for a stellar-mass black hole engine, such as a helium star merger, and the beaming-corrected kinetic energy in this scenario is consistent with the known distribution for long GRBs (E_K∼10^51 erg). The wide-angle jet scenario would instead require a progenitor involving prolonged accretion. We derive and show an intermediate or stellar-mass black hole tidal disruption event are viable possibilities. The beaming-corrected kinetic energy in this scenario is on the low end of the known distribution for relativistic SMBH TDEs (E_K∼10^50 erg). We disfavour an SMBH TDE due to lack of compatibility with the observed timescales. The detection of a jet shut off within the next year would favour a WD-IMBH TDE due to the shorter theoretical duration of super-Eddington accretion than the main-sequence TDE channels.

A tiny fraction (≪1%) of galaxies display luminous, high-ionization metal emission lines, which may be persistent or variable. These extreme coronal lines (ECLs) are produced when soft X-ray photons intercept dense gas (n≳10^6-7 cm^-3). The high X-ray flux required implicates intense nuclear activity, likely originating from tidal disruption events (TDEs) and active galactic nuclei (AGN). As ECLs are rarely seen even within these classes, their production may also require specific environmental conditions, but the details remain unclear (e.g., the geometry and volume filling factor of the ECL-producing gas). Here, we present the radio properties of a population of 27 low-redshift (z<0.3) ECL emitting galaxies (ECLEs), providing a unique and previously unexplored probe of the properties of the circumnuclear medium (CNM; ≲1 pc from the black hole) in these systems. We find that ∼ 50% of ECLEs produce radio synchrotron emission with luminosity and evolution consistent with TDEs and/or AGN. Radio spectral modeling of four ECLEs reveals that the ECL-producing region is (1) clumpy with a low volume filling factor (10^-5≲ f_V≲10^-2) and (2) likely distinct from the radio emitting region (implying, e.g., a clumpy toroidal geometry). For time-variable ECLEs, these are some of the first observational constraints on the CNM geometry in formerly quiescent galactic nuclei. The unique nature of ECLEs makes them an excellent high-energy laboratory to connect the physics of accretion, photoionization, and feedback in galactic nuclei, thus motivating continued multi-wavelength monitoring.

We present follow-up observations of the day-long, repeating gamma-ray burst (GRB) GRB 250702B with the Near Infrared Spectrograph on board the James Webb Space Telescope. Through the identification of narrow hydrogen emission lines at a consistent redshift of z = 1.036 ± 0.004, we calibrate the distance scale, and therefore the energetics, of this unique extragalactic transient. At this distance, the resulting γ -ray energy release is at least E _γ _,iso = 2.2 × 10 ^54 erg. We find no evidence for ongoing transient emission at the GRB position and exclude any accompanying supernova (SN) with a luminosity comparable to the Type Ic broad-line SN 2023lcr, though we are unable to rule out a fainter SN counterpart owing to high extinction. The inferred rate of such events, assuming at most one in the lifetime of Fermi, suggests that such bursts are very rare, with volumetric rates over 1000 times lower than normal high-luminosity long GRBs and >10 ^5 times lower than core-collapse SNe, when corrected for beaming. Furthermore, we find that the host galaxy is unique among GRB host galaxies and extremely rare in the general galaxy population, being extremely large and dusty and with high stellar mass. The identification of such an exotic GRB in such an unusual galaxy raises the possibility that the environment was important in the progenitor channel creating GRB 250702B.

Determining the energy, size, and velocity of synchrotron-emitting outflows is essential for testing models of their formation and evolution, but these quantities are often poorly constrained by observations alone. Equipartition analysis, therefore, provides a widely used framework for estimating these properties. Prior works have developed refinements to account for additional physical effects and other sources of energy (e.g., self-absorption, hot protons, and deviations from strict equipartition); however, these corrections are typically applied independently of one another, resulting in internal inconsistencies. In this work, we derive a self-consistent equipartition framework that accounts for the interdependence of various correction factors for Newtonian outflows and on- and off-axis relativistic jets. We implement our framework in an easy-to-use, publicly available code and apply it to study the tidal disruption events ASASSN-19bt and AT2019dsg, fast X-ray transient EP240414a, and active galactic nucleus J0231-0433. The interdependence of the corrections can increase energy estimates by a factor of 5, suggesting that the energies of other synchrotron sources may be similarly underestimated in the literature. These results indicate that simultaneously incorporating these correction factors is essential for determining accurate outflow properties and constraining launch mechanisms.

We present ongoing radio observations of the tidal disruption event (TDE) AT2018hyz, which was first detected in the radio at 972 days after disruption, following multiple non-detections from earlier searches. The new observations presented here span approximately 1370-2160 days and 0.88-240 GHz. We find that the light curves continue to rise at all frequencies during this time period, following a power law of about F t^3 (compared to F_nu t^5.7 at 972-1400 days), and reaching a peak luminosity of L 10^40 erg/s, comparable to the luminosity of the relativistic TDE Swift 1644+57 on the same timescale. The multi-frequency data indicate that the peak frequency does not significantly evolve over the 1030-day span of our observations, while the peak flux density increases by an order of magnitude. The observed behavior is consistent with two possible scenarios: (i) a delayed spherical outflow launched about 620 days post-disruption with a velocity of 0.3c and an energy of 10^50 erg, and (ii) a highly off-axis ( 80-90 deg) relativistic jet with a Lorentz factor of Gamma 8 and E_K 10^52 erg. Continued radio observations to capture the light curve peak, as well as VLBI observations, could distinguish between these scenarios.

GRB 250702B is a unique astrophysical transient characterised by its nature as a repeating gamma-ray trigger. Its properties include possible periodicity in its gamma-ray light curve, an X-ray counterpart that rose prior to the gamma-ray outbursts and faded quickly, and radio and infrared counterparts. These features are difficult to reconcile with most models of high energy transients but we show that they are compatible with a white dwarf bound to an intermediate mass black hole that is tidally stripped over multiple pericentre passages before being fully disrupted. In this model, accretion onto the black hole powers a mildly relativistic jet that produces the X-rays through internal processes and the infrared and radio counterparts through thermal emission and external shocks respectively but is unable to produce the gamma-ray emission on its own. We find that chaotic debris streams from the multiple stripping episodes can collide with a period roughly the same as the orbital period of the star. These shocks produce X-ray photons that are upscattered by the jet to produce the observed MeV gamma-ray emission. Future analysis of the jet properties will allow us to place firmer constraints on our model.

We present a systematic study of the currently available ALMA millimeter polarimetric sample of gamma-ray burst (GRB) afterglows. Our sample comprises 24 observations (20 new) of 11 long-duration GRBs spanning ≈0.1-87 days after the burst. We detect significant linear polarization in 8 observations across 6 events, with polarization degrees ranging from Π_L≈0.6% to 2.4%. For the remaining observations, we place deep upper limits (median Π_L≲1%). Multi-epoch observations reveal diverse polarization evolution. GRB 190114C yields the best-sampled Π_L for a radio afterglow to date, with early evolution favoring patchy magnetic fields in the reverse shock (RS) and later polarization broadly consistent with forward-shock (FS) models. GRB 220921A exhibits a rapid rise in polarization from Π_L≲0.4% to 2.4% over 1.9-6.8 days, inconsistent with toroidal RS magnetic-field models but broadly consistent with several FS random-field models. GRB 221009A yields the highest-significance polarization detections in the sample (Π_L≈1.4-1.6%), yet neither existing FS nor RS polarization models reproduce both the observed polarization evolution and the viewing geometry inferred from broadband afterglow modeling, with the exception of patchy fields in the RS. Deep upper limits for GRB 171205A rule out RS toroidal-field models for the published off-axis geometry, while a strong, single-epoch detection of GRB 190829A, if RS-dominated, requires a nearly on-axis geometry for toroidal-field configurations. Interpreting the observations within a patchy-field framework implies magnetic-field coherence scales of order θ_B∼10^-3-10^-2 rad. These observations demonstrate the diagnostic power of radio/mm polarimetry for probing the magnetic-field structure, emission region, and viewing geometry of relativistic GRB jets.

We present the results from an extensive broadband (radio to X-rays) observing campaign of the engine-driven Type Ib SN 2012au in the first 13 yr of evolution. The early time ( δt ≤ 190 days) radio and X-ray evolution is well described by conventional models of a forward shock interacting with a wind-like circumstellar medium (CSM; ρ _CSM ∝ r ^−2 ). However, starting at δt ≈ 6.7 yr, we detect a significant radio rebrightening. This late-time emission is dominated by a luminous component characterized by a broad and rapidly evolving spectral peak and a shallow optically thin spectral slope, F _ν ∝ ν ^−0.31 ± 0.02 . These properties imply a compact emitting region ( R ≲ 10 ^16 cm) expanding at a remarkably slow velocity ( v _s ≲ 500 km s ^−1 ) into a high-density environment ( n _e ≥ 10 ^4 cm ^−3 ), accompanied by a hard electron power-law index p ≈ 1.6. No soft or hard X-ray emission is detected at any epoch, indicating that high-energy radiation is either strongly absorbed or intrinsically absent. In the context of aspherical shock–CSM interaction models, these observations imply extreme properties of the CSM (geometry, density, and total mass) that lack clear astrophysical motivation. Instead, we show that the emergence of radiation from a newborn pulsar wind nebula (PWN) naturally explains the radio spectral evolution and high-energy limits, where the emission is governed by the adiabatic expansion of a relic pair plasma. We conclude that SN 2012au represents the most compelling candidate for a young, newborn PWN discovered to date, a scenario that can be directly tested with pending very long baseline interferometry observations.

We present an extensive photometric and spectroscopic ultraviolet–optical–infrared campaign on the luminous fast blue optical transient (LFBOT) AT 2024wpp over the first ∼100 days. AT 2024wpp is the most luminous LFBOT discovered to date, with L _pk ≈ (2–4) × 10 ^45 erg s ^−1 (5–10 times that of the prototypical AT 2018cow). This extreme luminosity enabled the acquisition of the most detailed LFBOT UV light curve thus far. In the first ∼45 days, AT 2024wpp radiated >10 ^51 erg, surpassing AT 2018cow by an order of magnitude and requiring a power source beyond the radioactive ^56 Ni decay of traditional supernovae. Like AT 2018cow, the UV–optical spectrum of AT 2024wpp is dominated by a persistently blue thermal continuum throughout our monitoring, with blackbody parameters at a peak of T > 30,000 K and R _BB / t ≈ 0.2 c –0.3 c . We find evidence for cooling until ∼10 days; thereafter, T ≳ 20,000 K is maintained. We interpret the featureless spectra as a consequence of continuous energy injection from a central source of high-energy emission that maintains high ejecta ionization. After 35 days, faint (equivalent width (EW) ≲ 10 Å) H and He spectral features with kinematically separate velocity components centered at 0 and −6400 km s ^−1 emerge, implying spherical symmetry deviations. A near-infrared excess of emission above the optical blackbody emerges between 20 and 30 days, with a power-law spectrum F _ν _,NIR ∝ ν ^−0.3 at 30 days. We interpret this distinct emission component as either reprocessing of early UV emission in a dust echo or free–free emission in an extended medium above the optical photosphere. LFBOT asphericity and multiple outflow components (including mildly relativistic ejecta), together with the large radiated energy, are naturally realized by super-Eddington accretion disks around neutron stars or black holes and their outflows.