arXiv subjects

Justyn R. Maund

Publications and source records attributed to Justyn R. Maund.

At least 37 records · Page 2Linked to original sources

arXiv2022

The Interaction of Supernova 2018evt with a Substantial Amount of Circumstellar Matter -- An SN1997cy-like Event

A rare class of supernovae (SNe) is characterized by strong interaction between the ejecta and several solar masses of circumstellar matter (CSM) as evidenced by strong Balmer-line emission. Within the first few weeks after the explosion, they may display spectral features similar to overluminous Type Ia SNe, while at later phase their observation properties exhibit remarkable similarities with some extreme case of Type IIn SNe that show strong Balmer lines years after the explosion. We present polarimetric observations of SN2018evt obtained by the ESO Very Large Telescope from 172 to 219 days after the estimated time of peak luminosity to study the geometry of the CSM. The nonzero continuum polarization decreases over time, suggesting that the mass loss of the progenitor star is aspherical. The prominent H$α$ emission can be decomposed into a broad, time-evolving component and an intermediate-width, static component. The former shows polarized signals, and it is likely to arise from a cold dense shell (CDS) within the region between the forward and reverse shocks. The latter is significantly unpolarized, and it is likely to arise from shocked, fragmented gas clouds in the H-rich CSM. We infer that SN2018evt exploded inside a massive and aspherical circumstellar cloud. The symmetry axes of the CSM and the SN appear to be similar. SN\,2018evt shows observational properties common to events that display strong interaction between the ejecta and CSM, implying that they share similar circumstellar configurations. Our preliminary estimate also suggests that the circumstellar environment of SN2018evt has been significantly enriched at a rate of $\sim0.1$ M$_\odot$ yr$^{-1}$ over a period of $>100$ yr.

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arXiv2022

Spectropolarimetry of the Thermonuclear Supernova 2021rhu: High Calcium Polarization 79 Days After Peak Luminosity

We report spectropolarimetric observations of the Type Ia supernova (SN) 2021rhu at four epochs: $-$7, +0, +36, and +79 days relative to its $B$-band maximum luminosity. A wavelength-dependent continuum polarization peaking at $3890 \pm 93$ Angstroms and reaching a level of $p_{\rm max}=1.78% \pm 0.02$% was found. The peak of the polarization curve is bluer than is typical in the Milky Way, indicating a larger proportion of small dust grains along the sightline to the SN. After removing the interstellar polarization, we found a pronounced increase of the polarization in the CaII near-infrared triplet, from $\sim$0.3% at day $-$7 to $\sim$2.5% at day +79. No temporal evolution in high-resolution flux spectra across the NaID and CaIIH&K features was seen from days +39 to +74, indicating that the late-time increase in polarization is intrinsic to the SN as opposed to being caused by scattering of SN photons in circumstellar or interstellar matter. We suggest that an explanation for the late-time rise of the CaII near-infrared triplet polarization may be the alignment of calcium atoms in a weak magnetic field through optical excitation/pumping by anisotropic radiation from the SN.

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arXiv2022

An asymmetric electron-scattering photosphere around optical tidal disruption events

A star crossing the tidal radius of a supermassive black hole will be spectacularly ripped apart with an accompanying burst of radiation. A few tens of such tidal disruption events (TDEs) have now been identified in the optical wavelengths, but the exact origin of the strong optical emission remains inconclusive. Here we report polarimetric observations of three TDEs. The continuum polarization is independent of wavelength, while emission lines are partially depolarized. These signatures are consistent with optical photons being scattered and polarized in an envelope of free electrons. An almost axisymmetric photosphere viewed from different angles is in broad agreement with the data, but there is also evidence for deviations from axial symmetry before the peak of the flare and significant time evolution at early times, compatible with the rapid formation of an accretion disk. By combining a super-Eddington accretion model with a radiative transfer code we generate predictions for the degree of polarization as a function of disk mass and viewing angle, and we show that the predicted levels are compatible with the observations, for extended reprocessing envelopes of $\sim$1000 gravitational radii. Spectropolarimetry therefore constitutes a new observational test for TDE models, and opens an important new line of exploration in the study of TDEs.

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arXiv2022

A hot and luminous source at the site of the fast transient AT2018cow at 2-3 years after its explosion

We report the discovery of a luminous late-time source at the position of the fast blue optical transient (FBOT) AT2018cow on images taken by the Hubble Space Telescope (HST) at 714 d and 1136 d after its explosion. This source is detected at both UV and optical wavelengths and has prominent H$α$ emission. It has a very stable brightness between the two epochs and a very blue spectral energy distribution (SED) consistent with $f_λ$ $\propto$ $λ^{-4.1 \pm 0.1}$, i.e. the Rayleigh-Jeans tail of a hot blackbody with a very high temperature of log($T$/K) $>$ 4.6 and luminosity of log($L$/$L_\odot$) $>$ 7.0. This late-time source is unlikely to be an unrelated object in chance alignment, or due to a light echo of AT2018cow. Other possible scenarios also have some difficulties in explaining this late-time source, including companion star(s), star cluster, the survived progenitor star, interaction with circumstellar medium (CSM), magnetar, or delayed accretion in a tidal disruption event (TDE). Long-term and multi-wavelength monitoring will help to resolve its nature and finally reveal the origin of the "Cow".

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arXiv2022

The Type Icn SN 2021csp: Implications for the Origins of the Fastest Supernovae and the Fates of Wolf-Rayet Stars

We present observations of SN 2021csp, the second example of a newly-identified type of supernova (Type Icn) hallmarked by strong, narrow, P Cygni carbon features at early times. The SN appears as a fast and luminous blue transient at early times, reaching a peak absolute magnitude of -20 within 3 days due to strong interaction between fast SN ejecta (v ~ 30000 km/s) and a massive, dense, fast-moving C/O wind shed by the WC-like progenitor months before explosion. The narrow line features disappear from the spectrum 10-20 days after explosion and are replaced by a blue continuum dominated by broad Fe features, reminiscent of Type Ibn and IIn supernovae and indicative of weaker interaction with more extended H/He-poor material. The transient then abruptly fades ~60 days post-explosion when interaction ceases. Deep limits at later phases suggest minimal heavy-element nucleosynthesis, a low ejecta mass, or both, and imply an origin distinct from that of classical Type Ic supernovae. We place SN 2021csp in context with other fast-evolving interacting transients, and discuss various progenitor scenarios: an ultrastripped progenitor star, a pulsational pair-instability eruption, or a jet-driven fallback supernova from a Wolf-Rayet star. The fallback scenario would naturally explain the similarity between these events and radio-loud fast transients, and suggests a picture in which most stars massive enough to undergo a WR phase collapse directly to black holes at the end of their lives.

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arXiv2021

An environmental analysis of the Type Ib SN 2019yvr and the possible presence of an inflated binary companion

SN 2019yvr is the second Type Ib supernova (SN) with a possible direct detection of its progenitor (system); however, the spectral energy distribution (SED) of the pre-explosion source appears much cooler and overluminous than an expected helium-star progenitor. Using Hubble Space Telescope (HST) images and MUSE integral-field-unit (IFU) spectroscopy, we find the SN environment contains three episodes of star formation; the low ejecta mass suggests the SN progenitor is most likely from the oldest population, corresponding to an initial mass of 10.4$^{+1.5}_{-1.3}$ $M_\odot$. The pre-explosion SED can be reproduced by two components, one for the hot and compact SN progenitor and one for a cool and inflated yellow hypergiant (YHG) companion that dominates the brightness. Thus, SN 2019yvr could possibly be the first Type Ib/c SN for which the progenitor's binary companion is directly detected on pre-explosion images. Both the low progenitor mass and the YHG companion suggest significant binary interaction during their evolution. Similar to SN 2014C, SN 2019yvr exhibits a metamorphosis from Type Ib to Type IIn, showing signatures of interaction with hydrogen-rich circumstellar material (CSM) at >150 days; our result supports enhanced pre-SN mass loss as an important process for hydrogen-poor stars at the low mass end of core-collapse SN progenitors.

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arXiv2021

Spectropolarimetry of the Type Ia SN 2019ein rules out significant global asphericity of the ejecta

Detailed spectropolarimetric studies may hold the key to probing the explosion mechanisms and the progenitor scenarios of Type Ia supernovae (SNe Ia). We present multi-epoch spectropolarimetry and imaging polarimetry of SN 2019ein, an SN Ia showing high expansion velocities at early phases. The spectropolarimetry sequence spans from $\sim -11$ to $+$10 days relative to peak brightness in the $B$-band. We find that the level of the continuum polarization of SN 2019ein, after subtracting estimated interstellar polarization, is in the range $0.0-0.3\%$, typical for SNe Ia. The polarization position angle remains roughly constant before and after the SN light-curve peak, implying that the inner regions share the same axisymmetry as the outer layers. We observe high polarization ($\sim 1\%$) across both the Si II $\lambda6355$ and Ca II near-infrared triplet features. These two lines also display complex polarization modulations. The spectropolarimetric properties of SN 2019ein rule out a significant departure from spherical symmetry of the ejecta for up to a month after the explosion. These observations disfavour merger-induced and double-detonation models for SN 2019ein. The imaging polarimetry shows weak evidence for a modest increase in polarization after $\sim 20$ days since the $B$-band maximum. If this rise is real and is observed in other SNe Ia at similar phases, we may have seen, for the first time, an aspherical interior similar to what has been previously observed for SNe IIP. Future polarization observations of SNe Ia extending to post-peak epochs will help to examine the inner structure of the explosion.

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arXiv2021

Toward a better understanding of supernova environments: a study of SNe 2004dg and 2012P in NGC 5806 with HST and MUSE

Core-collapse supernovae (SNe) are the inevitable fate of most massive stars. Since most stars form in groups, SN progenitors can be constrained with information of their environments. It remains challenging to accurately analyse the various components in the environment and to correctly identify their relationships with the SN progenitors. Using a combined dataset of VLT/MUSE spatially-resolved integral-field-unit (IFU) spectroscopy and HST/ACS+WFC3 high-spatial resolution imaging, we present a detailed investigation of the environment of the Type II-P SN 2004dg and Type IIb SN 2012P. The two SNe occurred in a spiral arm of NGC 5806, where a star-forming complex is apparent with a giant H II region. By modelling the ionised gas, a compact star cluster and the resolved stars, we derive the ages and extinctions of stellar populations in the vicinity of the SNe. The various components are consistent with a sequence of triggered star formation as the spiral density wave swept through their positions. For SNe 2004dg and 2012P, we identify their host stellar populations and derive initial masses of $10.0^{+0.3}_{-0.2}~M_\odot$ and $15.2^{+2.0}_{-1.0}~M_\odot$ for their progenitors, respectively. Both results are consistent with those from pre-explosion images or nebular-phase spectroscopy. SN 2012P is spatially coincident but less likely to be coeval with the star-forming complex. As in this case, star formation bursts on small scales may appear correlated if they are controlled by any physical processes on larger scales; this may lead to a high probability of chance alignment between older SN progenitors and younger stellar populations.

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arXiv2020

The changing-type SN 2014C may come from an 11-$M_\odot$ star stripped by binary interaction and violent eruption

SN 2014C was an unprecedented supernova (SN) that displayed a metamorphosis from Type Ib to Type IIn over $\sim$200 days. This transformation is consistent with a helium star having exploded in a cavity surrounded by a dense shell of the progenitor's stripped hydrogen envelope. For at least 5 years post-explosion, the ejecta continued to interact with an outer, extended component of circumstellar medium (CSM) that was ejected even before the dense shell. It is still unclear, however, what kind of progenitor could have undergone such a complicated mass-loss history before it produced this peculiar SN. In this paper, we report a new analysis of SN 2014C's host star cluster based on data from the Hubble Space Telescope (HST). By carefully fitting its spectral energy distribution (SED), we derive a precise cluster age of 20.0$^{+3.5}_{-2.6}$ Myr, which corresponds to the progenitor's lifetime assuming coevolution. Combined with binary stellar evolution models, we find that SN 2014C's progenitor may have been an $\sim$11-$M_\odot$ star in a relatively wide binary system. The progenitor's envelope was partially stripped by Case C or Case BC mass transfer via binary interaction, followed by a violent eruption that ejected the last hydrogen layer before terminal explosion. Thus, SN 2014C, in common with SNe 2006jc and 2015G, may be a third example that violent eruptions, with mass-loss rates matching luminous blue variable (LBV) giant eruptions, can also occur in much lower-mass massive stars if their envelopes are partially or completely stripped in interacting binaries.

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arXiv2020

First systematic high-precision survey of bright supernovae I. Methodology for identifying early bumps

Rapid variability before and near the maximum brightness of supernovae has the potential to provide a better understanding of nearly every aspect of supernovae, from the physics of the explosion up to their progenitors and the circumstellar environment. Thanks to modern time-domain optical surveys, which are discovering supernovae in the early stage of their evolution, we have the unique opportunity to capture their intraday behavior before maximum. We present high-cadence photometric monitoring (on the order of seconds-minutes) of the optical light curves of three Type Ia and two Type II SNe over several nights before and near maximum light, using the fast imagers available on the 2.3~m Aristarchos telescope at Helmos Observatory and the 1.2~m telescope at Kryoneri Observatory in Greece. We applied differential aperture photometry techniques using optimal apertures and we present reconstructed light curves after implementing a seeing correction and the Trend Filtering Algorithm(TFA). TFA yielded the best results, achieving a typical precision between 0.01-0.04~mag. We did not detect significant bumps with amplitudes greater than 0.05~mag in any of the SNe targets in the VR-, R-, and I- bands light curves obtained. We measured the intraday slope for each light curve, which ranges between -0.37-0.36 mag/day in broadband VR, -0.19-0.31 mag/day in R band, and -0.13-0.10 mag/day in I band. We used SNe light curve fitting templates for SN 2018gv, SN 2018hgc and SN 2018hhn to photometrically classify the light curves and to calculate the time of maximum. We provide values for the maximum of SN 2018zd after applying a low-order polynomial fit and SN 2018hhn for the first time. We suggest monitoring early supernovae light curves in hotter (bluer) bands with a cadence of hours as a promising way of investigating the post-explosion photometric behavior of the progenitor stars.

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arXiv2019

Linear spectropolarimetry of 35 Type Ia Supernovae with VLT/FORS: An analysis of the Si II line polarization

Spectropolarimetry enables us to measure the geometry and chemical structure of the ejecta in supernova explosions, which is fundamental for the understanding of their explosion mechanism(s) and progenitor systems. We collected archival data of 35 Type Ia Supernovae (SNe Ia), observed with FORS on the Very Large Telescope at 127 epochs in total. We examined the polarization of the Si II $λ$6355 $Å$ line (p$_{\rm Si II}$) as a function of time which is seen to peak at a range of various polarization degrees and epochs relative to maximum brightness. We reproduced the $Δ$m$_{15}$-p$_{\rm Si II}$ relationship identified in a previous study, and show that subluminous and transitional objects display polarization values below the $Δ$m$_{15}$-p$_{\rm Si II}$ relationship for normal SNe Ia. We found a statistically significant linear relationship between the polarization of the Si II $λ$6355 $Å$ line before maximum brightness and the Si II line velocity and suggest that this, along with the $Δ$m$_{15}$-p$_{\rm Si II}$ relationship, may be explained in the context of a delayed-detonation model. In contrast, we compared our observations to numerical predictions in the $Δ$m$_{15}$-v$_{\rm Si II}$ plane and found a dichotomy in the polarization properties between Chandrasekhar and sub-Chandrasekhar mass explosions, which supports the possibility of two distinct explosion mechanisms. A subsample of SNe display evolution of loops in the $q$-$u$ plane that suggests a more complex Si structure with depth. This insight, which could not be gleaned from total flux spectra, presents a new constraint on explosion models. Finally, we compared our statistical sample of the Si II polarization to quantitative predictions of the polarization levels for the double-detonation, delayed-detonation, and violent-merger models.

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arXiv2019

The origin of the late-time luminosity of supernova 2011dh

Due to the small amount of hydrogen (${\leq 0.1M_{\odot}}$) remaining on the surface of their progenitors, Type IIb supernovae are sensitive probes of the mass loss processes of massive stars towards the ends of their lives, including the role of binarity. We report late-time Hubble Space Telescope observations of SN 2011dh in M51, and a brief period of re-brightening and plateau in the photometric light curve, from $1.8$ to $6.2$ years after the explosion. These observations exclude the role of circumstellar interaction, however a slow rotating magnetar, a significant quantity of radioactive elements or a light echo could be responsible for the late-time luminosity observed at $t > 1000\mathrm{d}$. If the late-time light curve is powered by the decay of radioactive elements, SN~2011dh is required to have produced $\sim 2.6 \times 10^{-3}\,M_{\odot}$ of $\mathrm{^{44}Ti}$, which is significantly in excess of the amount inferred from earlier nebular spectra of SN 2011dh itself or measured in the Cas A SN remnant. The evolution of the brightness and the colour of the late-time light curve also supports the role of a light echo originating from dust with a preferred geometry of a disk of extent $\sim 1.8$ to $\sim 2.7\,\mathrm{pc}$ from the SN, consistent with a wind-blown bubble. Accounting for the long term photometric evolution due to a light echo, the flux contribution from a surviving binary companion at ultraviolet wavelengths can be isolated and corresponds to a star of $\sim 9 - 10M_{\odot}$.

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arXiv2019

The Type II-Plateau Supernova 2017eaw in NGC 6946 and Its Red Supergiant Progenitor

We present extensive optical photometric and spectroscopic observations, from 4 to 482 days after explosion, of the Type II-plateau (II-P) supernova (SN) 2017eaw in NGC 6946. SN 2017eaw is a normal SN II-P intermediate in properties between, for example, SN 1999em and SN 2012aw and the more luminous SN 2004et, also in NGC 6946. We have determined that the extinction to SN 2017eaw is primarily due to the Galactic foreground and that the SN site metallicity is likely subsolar. We have also independently confirmed a tip-of-the-red-giant-branch (TRGB) distance to NGC 6946 of 7.73+/-0.78 Mpc. The distances to the SN that we have also estimated via both the standardized candle method and expanding photosphere method corroborate the TRGB distance. We confirm the SN progenitor identity in pre-explosion archival Hubble Space Telescope (HST) and Spitzer Space Telescope images, via imaging of the SN through our HST Target of Opportunity program. Detailed modeling of the progenitor's spectral energy distribution indicates that the star was a dusty, luminous red supergiant consistent with an initial mass of ~15 Msuns.

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arXiv2019

The Young and Nearby Normal Type Ia Supernova 2018gv: UV-Optical Observations and the Earliest Spectropolarimetry

The non-detection of companion stars in Type Ia supernova (SN) progenitor systems lends support to the notion of double-degenerate (DD) systems and explosions triggered by the merging of two white dwarfs. This very asymmetric process should lead to a conspicuous polarimetric signature. By contrast, observations consistently find very low continuum polarization as the signatures from the explosion process largely dominate over the pre-explosion configuration within several days. Critical information about the interaction of the ejecta with a companion and any circumstellar matter is encoded in the early polarization spectra. In this study, we obtain spectropolarimetry of SN\,2018gv with the ESO Very Large Telescope at $-$13.6 days relative to the $B-$band maximum light, or $\sim$5 days after the estimated explosion --- the earliest spectropolarimetric observations to date of any Type Ia SN. These early observations still show a low continuum polarization ($\lesssim$0.2\%) and moderate line polarization (0.30$\pm$0.04\% for the prominent \ion{Si}{2} $λ$6355 feature and 0.85$\pm$0.04\% for the high-velocity Ca component). The high degree of spherical symmetry implied by the low line and continuum polarization at this early epoch is consistent with explosion models of delayed detonations and is inconsistent with the merger-induced explosion scenario. The dense UV and optical photometry and optical spectroscopy within the first $\sim$100 days after the maximum light indicate that SN\,2018gv is a normal Type Ia SN with similar spectrophotometric behavior to SN\,2011fe.

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arXiv2019

Probing the Final-stage Progenitor Evolution for Type IIP Supernova 2017eaw in NGC 6946

We presented a detailed analysis of progenitor properties of type IIP supernova 2017eaw in NGC 6946, based on the pre-explosion images and early-time observations obtained immediately after the explosion. An unusually red star, with M$_{F814W}$ = $-$6.9 mag and m$_{F606W}$$-$ m$_{F814W}=$2.9$\pm$0.2 mag, can be identified at the SN position in the pre-discovery Hubble Space Telescope(HST) images taken in 2016. The observed spectral energy distribution of this star, covering the wavelength of 0.6-2.0$\ \mathrm{μm}$, matches that of an M4-type red supergiant (RSG) with a temperature of about 3550 K. These results suggest that SN 2017eaw has a RSG progenitor with an initial mass of 12$\pm$2 M$_\odot$. The absolute F814W-band magnitude of this progenitor star is found to evolve from $-$7.2 mag in 2004 to $-$6.9 mag in 2016. Such a dimming effect is, however, unpredicted for a RSG in its neon/oxygen burning phase when its luminosity should modestly increase. The spectrum of SN 2017eaw taken a few hours after discovery clearly shows a narrow H$_α$ emission feature blueshifted by $\sim$160 km s$^{-1}$. This narrow component disappeared in the spectrum taken two days later, suggesting the presence of a circumstellar material (CSM) shell (i.e., at a distance of $<$2.1-4.3$\times$10$^{14}$ cm). Combining the inferred distance with the expansion velocity of the CSM, we suggest that the progenitor of SN 2017eaw should have experienced violent mass loss at about 1-2 years prior to explosion, perhaps invoked by pulsational envelop ejection. This mechanism may help explain its luminosity decline in 2016 as well as the lack of detections of RSGs with initial mass in the range of 17 M$_\odot<$ M $<$ 25 M$_\odot$ as progenitors of SNe IIP.

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arXiv2018

Testing the magnetar scenario for superluminous supernovae with circular polarimetry

Superluminous supernovae (SLSNe) are at least $\sim$5 times more luminous than common supernovae (SNe). Especially hydrogen-poor SLSN-I are difficult to explain with conventional powering mechanisms. One possible scenario that might explain such luminosities is that SLSNe-I are powered by an internal engine, such as a magnetar or an accreting black hole. Strong magnetic fields or collimated jets can circularly polarize light. In this work, we measured circular polarization of two SLSNe-I with the FOcal Reducer and low dispersion Spectrograph (FORS2) mounted at the ESO's Very Large Telescope (VLT). PS17bek, a fast evolving SLSN-I, was observed around peak, while OGLE16dmu, a slowly evolving SLSN-I, was observed 100 days after maximum. Neither SLSN shows evidence of circularly polarized light, however, these non-detections do not rule out the magnetar scenario as the powering engine for SLSNe-I. We calculate the strength of the magnetic field and the expected circular polarization as a function of distance from the magnetar, which decreases very fast. Additionally, we observed no significant linear polarization for PS17bek at four epochs, suggesting that the photosphere near peak is close to spherical symmetry.

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arXiv2017

The very young resolved stellar populations around stripped-envelope supernovae

The massive star origins for Type IIP supernovae (SNe) have been established through direct detection of their red supergiants progenitors in pre-explosion observations; however, there has been limited success in the detection of the progenitors of H-deficient SNe. The final fate of more massive stars, capable of undergoing a Wolf-Rayet phase, and the origins of Type Ibc SNe remains debated, including the relative importance of single massive star progenitors or lower mass stars stripped in binaries. We present an analysis of the ages and spatial distributions of massive stars around the sites of 23 stripped-envelope SNe, as observed with the Hubble Space Telescope, to probe the possible origins of the progenitors of these events. Using a Bayesian stellar populations analysis scheme, we find characteristic ages for the populations observed within $150\,\mathrm{pc}$ of the target Type IIb, Ib and Ic SNe to be $\log (t) = 7.20$, $7.05$ and $6.57$, respectively. The Type Ic SNe in the sample are nearly all observed within $100\,\mathrm{pc}$ of young, dense stellar populations. The environment around SN 2002ap is an important exception both in terms of age and spatial properties. These findings may support the hypothesis that stars with $M_{init} > 30M_{\odot}$ produce a relatively large proportion of Type Ibc SNe, and that these SN subtypes arise from progressively more massive progenitors. Significantly higher extinctions are derived towards the populations hosting these SNe than previously used in analysis of constraints from pre-explosion observations. The large initial masses inferred for the progenitors are in stark contrast with the low ejecta masses estimated from SN light curves.

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arXiv2017

Bridging the Gap: From Massive Stars to Supernovae

Almost since the beginning, massive stars and their resultant supernovae have played a crucial role in the Universe. These objects produce tremendous amounts of energy and new, heavy elements that enrich galaxies, encourage new stars to form and sculpt the shapes of galaxies we see today. The end of millions of years of massive star evolution and the beginning of hundreds or thousands of years of supernova evolution are separated by a matter of a few seconds, in which some of the most extreme physics found in the Universe causes the explosive and terminal disruption of the star. Key questions remain unanswered in both the studies of how massive stars evolve and the behaviour of supernovae, and it appears the solutions may not lie on just one side of the explosion or the other or in just the domain of the stellar evolution or the supernova astrophysics communities. The need to view massive star evolution and supernovae as continuous phases in a single narrative motivated the Theo Murphy international scientific meeting "Bridging the gap: from massive stars to supernovae" at Chicheley Hall in June 2016, with the specific purpose to simultaneously address the scientific connections between theoretical and observational studies of massive stars and their supernovae, through engaging astronomers from both communities.

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