adsabs/AstroCLIMB huggingface dataset:
Paper: Light Curves of the Explosion of ONe White Dwarf + CO White Dwarf Merger Remnant and Type Icn Supernovae
Authors: Chengyuan Wu, Shuai Zha, Yongzhi Cai, Zhengyang Zhang, Yi Yang, Danfeng Xiang, Weili Lin, Xiaofeng Wang, Bo Wang
Figure caption: The comparison between light curves from the explosions of double WD merger remnants and the bolometric light curves of three SNe Icn. In the light-curve simulations, the radius of progenitor is R = 100 R ⊙, the ejecta mass is M ej ≈ 0.468 M ⊙, and the mass of nickel ﹩{M}_{{}^{56}\mathrm{Ni}}=0.01{M}_{\odot }﹩, fully mixed into the ejecta. For the property of CSM, the wind velocity is v = 1000 km s−1, the wind density parameter is w ≈ 3.15 × 1017 g cm−1, and the mass of the CSM is M CSM = 0.025 M ⊙. Solid lines with different colors represent the light curves from our simulations with different explosive energies (the CSM interaction and radioactive decay from 56Ni are considered). Dashed lines represent the simulated light curves with explosive energy E = 0.1 B but without considering radioactive decay from 56Ni (orange dotted line) and without considering both CSM interaction and radioactive decay from 56Ni (black dotted line). For some of the models, the simulations terminate at 23 days after explosions in order to save the calculation time. Green circles, blue squares, and red triangles with error bars represent the bolometric light curves of SN 2019jc, SN 2019hgp, and SN 2021csp, respectively.
Paper: Light Curves of the Explosion of ONe White Dwarf + CO White Dwarf Merger Remnant and Type Icn Supernovae
Authors: Chengyuan Wu, Shuai Zha, Yongzhi Cai, Zhengyang Zhang, Yi Yang, Danfeng Xiang, Weili Lin, Xiaofeng Wang, Bo Wang
Figure caption: Properties of the merger remnant before light-curve calculations. Panels (a) and (b) represent the density profile and the enclosed mass as the function of radius of the merger remnant before explosion. Blue squares, green circles, and red triangles represent the different mass cuts before energy injection. Panels (c) and (d) represent the elemental abundance profile and the density and velocity profiles of the 0.6 M ⊙ ejecta at the moment when shock wave reached the position at 0.05 M ⊙ beneath the surface. Panel (c) also shows the elemental abundance distribution in considering 56Ni with half and full mixing. Panel (d) also shows the properties of CSM with different wind velocities (wind mass-loss rate of 0.5 M ⊙ yr−1 lasts for 0.1 yr prior to the SN explosion).
Paper: Light Curves of the Explosion of ONe White Dwarf + CO White Dwarf Merger Remnant and Type Icn Supernovae
Authors: Chengyuan Wu, Shuai Zha, Yongzhi Cai, Zhengyang Zhang, Yi Yang, Danfeng Xiang, Weili Lin, Xiaofeng Wang, Bo Wang
Figure caption: Light curves from the explosions of double WD merger remnants with different initial parameters, demonstrating how the parameters alter the light curves. Panel (a): the effect of ejecta mass (M ej). Panel (b): the effect of explosion energy (E). Panel (c): the effect of 56Ni mass (﹩{M}_{{}^{56}\mathrm{Ni}}﹩) and mixing. Panel (d): the effect of CSM properties. Numbers (1)–(4) in panel (a) represent the four evolutionary phases mentioned in Section 3.
Paper: Light Curves of the Explosion of ONe White Dwarf + CO White Dwarf Merger Remnant and Type Icn Supernovae
Authors: Chengyuan Wu, Shuai Zha, Yongzhi Cai, Zhengyang Zhang, Yi Yang, Danfeng Xiang, Weili Lin, Xiaofeng Wang, Bo Wang
Figure caption: Additional properties of the merger remnant (M ej = 0.60 M ⊙, E = 1.0 × 1050 erg) after explosion. Panels (a) and (b): blackbody temperature, density, radius, and velocity as functions of time. Panel (c): Rosseland mean opacity at the photosphere as a function of temperature.
Paper: JWST’s First Glimpse of a z > 2 Forming Cluster Reveals a Top-heavy Stellar Mass Function
Authors: Hanwen Sun, Tao Wang, Ke Xu, Emanuele Daddi, Qing Gu, Tadayuki Kodama, Anita Zanella, David Elbaz, Ichi Tanaka, Raphael Gobat, Qi Guo, Jiaxin Han, Shiying Lu, Luwenjia Zhou
Figure caption: Comparison of the SMF under two different incompleteness-correction procedures. The blue solid line is the SMF corrected by Equation (D1) (identical with the blue line in Figure 4). The red dashed line is the SMF corrected by Equation (D2).
Paper: Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy
Authors: Masayuki Kuzuhara, Akihiko Fukui, John H. Livingston, José A. Caballero, Jerome P. de Leon, Teruyuki Hirano, Yui Kasagi, Felipe Murgas, Norio Narita, Masashi Omiya, Jaume Orell-Miquel, Enric Palle, Quentin Changeat, Emma Esparza-Borges, Hiroki Harakawa, Coel Hellier, Yasunori Hori, Kai Ikuta, Hiroyuki Tako Ishikawa, Takanori Kodama, Takayuki Kotani, Tomoyuki Kudo, Juan C. Morales, Mayuko Mori, Evangelos Nagel, Hannu Parviainen, Volker Perdelwitz, Ansgar Reiners, Ignasi Ribas, Jorge Sanz-Forcada, Bun'ei Sato, Andreas Schweitzer, Hugo M. Tabernero, Takuya Takarada, Taichi Uyama, Noriharu Watanabe, Mathias Zechmeister, Néstor Abreu García, Wako Aoki, Charles Beichman, Víctor J. S. Béjar, Timothy D. Brandt, Yéssica Calatayud-Borras, Ilaria Carleo, David Charbonneau, Karen A. Collins, Thayne Currie, John P. Doty, Stefan Dreizler, Gareb Fernández-Rodríguez, Izuru Fukuda, Daniel Galán, Samuel Geraldía-González, Josafat González-Rodríguez, Yuya Hayashi, Christina Hedges, Thomas Henning, Klaus Hodapp, Masahiro Ikoma, Keisuke Isogai, Shane Jacobson, Markus Janson, Jon M. Jenkins, Taiki Kagetani, Eiji Kambe, Yugo Kawai, Kiyoe Kawauchi, Eiichiro Kokubo, Mihoko Konishi, Judith Korth, Vigneshwaran Krishnamurthy, Takashi Kurokawa, Nobuhiko Kusakabe, Jungmi Kwon, Andrés Laza-Ramos, Florence Libotte, Rafael Luque, Alberto Madrigal-Aguado, Yuji Matsumoto, Dimitri Mawet, Michael W. McElwain, Pedro Pablo Meni Gallardo, Giuseppe Morello, Sara Muñoz Torres, Jun Nishikawa, Stevanus K. Nugroho, Masahiro Ogihara, Alberto Peláez-Torres, David Rapetti, Manuel Sánchez-Benavente, Martin Schlecker, Sara Seager, Eugene Serabyn, Takuma Serizawa, Monika Stangret, Aoi Takahashi, Huan-Yu Teng, Motohide Tamura, Yuka Terada, Akitoshi Ueda, Tomonori Usuda, Roland Vanderspek, Sébastien Vievard, David Watanabe, Joshua N. Winn, Maria Rosa Zapatero Osorio
Figure caption: Midtransit times of Gliese 12 b measured in the TESS (black) and MuSCAT series (green) data with the best-fit linear ephemeris subtracted, showing no significant TTVs. Note that the measurement with large error bars (the third data point from TESS) comes from a partial transit (transit epoch = 29).
Paper: Light Curves of the Explosion of ONe White Dwarf + CO White Dwarf Merger Remnant and Type Icn Supernovae
Authors: Chengyuan Wu, Shuai Zha, Yongzhi Cai, Zhengyang Zhang, Yi Yang, Danfeng Xiang, Weili Lin, Xiaofeng Wang, Bo Wang
Figure caption: Panels (a) and (b): similar to Figure 4, but for the evolution of blackbody temperature (panel (a)) and blackbody radius (panel (b)). Panels (c) and (d): multiband light curves for double WD merger remnants with different explosion energies.
Paper: The Interplay between the Initial Mass Function and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities
Authors: Shyam H. Menon, Lachlan Lancaster, Blakesley Burkhart, Rachel S. Somerville, Avishai Dekel, Mark R. Krumholz
Figure caption: The UV luminosity per unit mass of stars: (i) for a given slope at the high-mass end of the IMF (α; left panel) and (ii) for a fixed Salpeter slope but different upper stellar mass limits (﹩{M}_{\max }﹩), both normalized by its counterpart for a standard Chabrier IMF—i.e., a Salpeter slope (i.e., α = –2.35) and an upper mass limit of 120 M ☉. These values have been obtained with the SLUG stellar population synthesis code. The peak mass of the IMF and its shape are kept identical in this calculation—only the high-mass slope and the upper mass limit are varied independently. We use this range of values (ΨUV ∼ 1–10 ΨSalpeter) to motivate the parameter space we explore.
Paper: The Interplay between the Initial Mass Function and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities
Authors: Shyam H. Menon, Lachlan Lancaster, Blakesley Burkhart, Rachel S. Somerville, Avishai Dekel, Mark R. Krumholz
Figure caption: The SFE as a function of time for our simulations. ΨUV = 1, 4, and 10 ΨFiducial are represented by dashed–dotted, dashed, and solid lines, respectively; colors indicate the different metallicities we explore, and the two panels represent the different Σcloud values in our simulation suite (Table 1). All our simulations undergo rapid collapse (over t ≲ 2t ff) and star formation followed by a saturation in ϵ * at the point when feedback is able to counteract the collapse; this saturation point is clearly different across our runs.
Paper: The Interplay between the Initial Mass Function and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities
Authors: Shyam H. Menon, Lachlan Lancaster, Blakesley Burkhart, Rachel S. Somerville, Avishai Dekel, Mark R. Krumholz
Figure caption: Gas surface density distributions at a time t = 4t ff for the Σcloud = 3.2 × 104 M ☉ pc−2 runs with increasing ΨUV (left to right) at Z = Z ⊙ (top) and Z = 0.01 Z ⊙ (bottom). We can see the general trend of a stronger impact of feedback at higher ΨUV and Z, as evidenced by the presence/absence of outflows in the velocity distribution, which are driven by radiation pressure on dust. The SFE (ϵ *; annotated at the top left of each panel) is high in all these cases, except when both ΨUV and Z are high. Comparison of the achieved ϵ * in the top right and bottom right panels demonstrates that a drop in Z can counteract the effects of a higher ΨUV.
Paper: The Interplay between the Initial Mass Function and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities
Authors: Shyam H. Menon, Lachlan Lancaster, Blakesley Burkhart, Rachel S. Somerville, Avishai Dekel, Mark R. Krumholz
Figure caption: The final integrated cloud-scale SFE (ϵ *,f) obtained in all of our simulations—scaled by the value obtained for a run without feedback (ϵ *,NoFB)—shown as a function of ΨUV. We indicate lines and their slopes to guide the eye (no fitting). We can see that there is a general trend of decreasing ϵ *,f with ΨUV; however, a lower Z can at least partly compensate for this decrease—much more so for the higher Σcloud cases (right panel). The trend for the higher Σcloud case is also clearly nonlinear. These trends are likely driven by the differing levels of momentum imparted by radiation pressure on dust across our simulations (see Section 3.3).
Paper: Inferring the Interstellar Magnetic Field Direction from Energetic Neutral Atom Observations of the Heliotail
Authors: M. Kornbleuth, M. Opher, M. A. Dayeh, J. M. Sokół, Y. Chen, E. Powell, D. L. Turner, I. Baliukin, K. Dialynas, V. Izmodenov
Figure caption: Vectors connecting the north/south lobe centers from modeled ENAs and IBEX data in the heliotail extracted from the model/data (left panels) and shifted such that the midpoints of the vectors are centered on an ecliptic longitude and latitude of (0°, 0°) (right panels). Included is the vector for the IBEX data corresponding to the years 2012–2013 (black), 2014–2015 (orange), and 2016–2017 (turquoise) from Dayeh et al. (2022). Top: comparison with changing solar wind profile and solar magnetic field (Cases 1–4). Cases with latitudinally varying solar wind profiles are represented with solid lines, and cases with uniform solar wind profiles are represented with dashed lines. The arrows indicate change in lobe center over time. Arrow colors reflect the line color of the initial lobe center. Middle: comparison with changing B ISM orientation (Cases 5–8). Bottom: comparison of changing B ISM magnitude and n  p,ISM (Cases 9–11).
Paper: Inferring the Interstellar Magnetic Field Direction from Energetic Neutral Atom Observations of the Heliotail
Authors: M. Kornbleuth, M. Opher, M. A. Dayeh, J. M. Sokół, Y. Chen, E. Powell, D. L. Turner, I. Baliukin, K. Dialynas, V. Izmodenov
Figure caption: Evolution of the north lobe (NL) and south lobe (SL) centers with changing solar wind profile and solar magnetic field. ENA sky maps show flux centered on the downwind (tail) direction that is normalized to the maximum flux in each map corresponding to Cases 1–4 listed in Table 1. For each map, the lobe center is displayed as the zeroed (blue) pixel within each north/south heliotail lobe. Top: Case 1 (left) corresponds to 2008-averaged solar minimum conditions with a weak solar magnetic field (B  r,SW = 2.94 μG), while Case 2 (right) corresponds to 2014-averaged solar maximum conditions with a weak solar magnetic field (B  r,SW = 44.4 μG). Bottom: Case 3 (left) corresponds to a uniform slow solar wind (e.g., solar-maximum-like conditions) with a weak solar magnetic field, and Case 4 (right) also has a uniform slow solar wind, but with a strong solar magnetic field (B  r,SW = 64.5 μG).
Paper: Inferring the Interstellar Magnetic Field Direction from Energetic Neutral Atom Observations of the Heliotail
Authors: M. Kornbleuth, M. Opher, M. A. Dayeh, J. M. Sokół, Y. Chen, E. Powell, D. L. Turner, I. Baliukin, K. Dialynas, V. Izmodenov
Figure caption: Cartoon depicting a tail-centered Mollweide projection showing the inclination angle (ω) of the high-latitude heliotail lobes. The inclination angle is defined here as the angle of the north/south lobe centers relative to the solar meridian. λ and β correspond to the ecliptic longitude and latitudinal coordinates of each lobe center, respectively, with NL and SL denoting the north and south lobes, respectively.
Paper: Uncovering the Ghostly Remains of an Extremely Diffuse Satellite in the Remote Halo of NGC 253 
Authors: Sakurako Okamoto, Annette M. N. Ferguson, Nobuo Arimoto, Itsuki Ogami, Rokas Žemaitis, Masashi Chiba, Mike J. Irwin, In Sung Jang, Jin Koda, Yutaka Komiyama, Myung Gyoon Lee, Jeong Hwan Lee, Michael R. Rich, Masayuki Tanaka, Mikito Tanaka
Figure caption: Left: the HSC pointings around NGC  253 overlaid on the Digitized Sky Survey image using the Aladin Sky Atlas (Bonnarel et al. 2000). The orange tiles indicate the pointing where SNFC-dw1 is discovered. The location of SNFC-dw1 and the previously known satellites within the footprint are indicated. Right: the spatial distribution of RGB stars selected using the polygon in Figure 2(a). The color of each point represents the (g − i)0 color of the star with transparency. The dotted ellipses indicate the 2 × R 25 and 4 × R 25 radii of NGC 253 (de Vaucouleurs et al. 1991), assuming b/a = 0.7. The solid and dashed circles show the circular radius of 9′ centered on SNFC-dw1 and a nearby reference field. The 2.5 × R  h  of the two known dwarf satellites within the FOV are also shown as solid lines and labeled. Lower middle: the smoothed density map of metal-poor RGB stars centered on SNFC-dw1 and selected within the left part of the solid polygon of Figure 2(b). The magenta cross shows the estimated centroid of the structure, of which the coordinate is shown in Table 1. The dashed line shows the fitted R  h  of the Sérsic profile. The black points represent the TP-AGB candidates. Gray-shaded areas are the masked regions affected by saturated foreground stars. The white arrow indicates the direction toward the NGC 253 center.
Paper: Uncovering the Ghostly Remains of an Extremely Diffuse Satellite in the Remote Halo of NGC 253 
Authors: Sakurako Okamoto, Annette M. N. Ferguson, Nobuo Arimoto, Itsuki Ogami, Rokas Žemaitis, Masashi Chiba, Mike J. Irwin, In Sung Jang, Jin Koda, Yutaka Komiyama, Myung Gyoon Lee, Jeong Hwan Lee, Michael R. Rich, Masayuki Tanaka, Mikito Tanaka
Figure caption: Dereddened Hess diagrams of stellar objects in NGC 253, the SNFC-dw1 region, a nearby reference field, and the field-subtracted SNFC-dw1 region. The bin sizes are 0.15 mag in the x-axis and 0.1 mag in the y-axis. (a) Stars within an elliptical annulus of 2 × R 25 < r <4 × R 25 centered on NGC 253, assuming b/a = 0.7. The solid polygon indicates the area used to select RGB stars for the right panel of Figure 1. PARSEC isochrones of age 10 Gyr and [M/H] = −2.2, −1.8, −1.4, −1.0, −0.7, and −0.4 are shifted to NGC 253's distance and overlaid as solid lines (Radburn-Smith et al. 2011; Bressan et al. 2012). (b) Stars within a circular radius of 9′ of SNFC-dw1. A 10 Gyr isochrone of [M/H] = −1.8 is shifted to the estimated SNFC-dw1 distance and overlaid. The dashed line in the solid polygon is used to separate the metal-poor RGB stars. The orange solid parallelogram above the RGB selection box is used to select TP-AGB candidates. (c) Stellar objects in a reference field, selected as an equal area region that lies at the same elliptical radius from NGC 253 as SNFC-dw1. (d) The field-subtracted Hess diagram of SNFC-dw1, created by subtracting panel (c) from (b). The gray color indicates negative values.
Paper: Uncovering the Ghostly Remains of an Extremely Diffuse Satellite in the Remote Halo of NGC 253 
Authors: Sakurako Okamoto, Annette M. N. Ferguson, Nobuo Arimoto, Itsuki Ogami, Rokas Žemaitis, Masashi Chiba, Mike J. Irwin, In Sung Jang, Jin Koda, Yutaka Komiyama, Myung Gyoon Lee, Jeong Hwan Lee, Michael R. Rich, Masayuki Tanaka, Mikito Tanaka
Figure caption: Upper: the luminosity–size relation. The purple symbols are known NGC 253 satellites (Martínez-Delgado et al. 2021; Mutlu-Pakdil et al. 2022). The yellow squares are UDGs in the Coma cluster (van Dokkum et al. 2015). The filled circles show LG dSphs from (McConnachie 2012, updated in 2021 January). The open squares with names are particularly diffuse dSphs (Toloba et al. 2016; Torrealba et al. 2019; Crnojević et al. 2019; Collins et al. 2020; Ji et al. 2021; Savino et al. 2022; Žemaitis et al. 2023). Lower: the luminosity–metallicity relation of nearby dSphs. The filled and open black squares represent SNFC-dw1 with [α/Fe] = 0.0 and 0.32 dex, respectively. The solid and dotted lines show the Kirby et al. (2013) relation with the 1σ deviation.
Paper: Uncovering the Ghostly Remains of an Extremely Diffuse Satellite in the Remote Halo of NGC 253 
Authors: Sakurako Okamoto, Annette M. N. Ferguson, Nobuo Arimoto, Itsuki Ogami, Rokas Žemaitis, Masashi Chiba, Mike J. Irwin, In Sung Jang, Jin Koda, Yutaka Komiyama, Myung Gyoon Lee, Jeong Hwan Lee, Michael R. Rich, Masayuki Tanaka, Mikito Tanaka
Figure caption: Metallicity distribution of RGB stars derived using the (g − i)0 color. The open histogram shows the completeness-corrected MDF, and the shaded histogram illustrates the contaminant-subtracted MDF using the reference field. The solid line shows a Gaussian fit to the contaminant-subtracted MDF.
Paper: An Early Dark Matter–dominated Phase in the Assembly History of Milky Way–mass Galaxies Suggested by the TNG50 Simulation and JWST Observations
Authors: Anna de Graaff, Annalisa Pillepich, Hans-Walter Rix
Figure caption: Baryonic mass fraction within the stellar half-mass radius (TNG50) and the emission line half-light radius (JWST; de Graaff et al. 2024) of galaxies vs. total stellar mass. Throughout, by baryonic fraction we mean the ratio between the mass in gas and stars and the total mass of the galaxy (see Equation (1)). The TNG50 simulation predicts low baryon fractions for M * < 109 M ⊙ and a sharp increase in f baryon toward higher masses. The half-mass radii are small (∼1 kpc in physical units) and, at fixed stellar mass, are anticorrelated with the baryon fraction. With the exception of one source, which may have high f baryon due to an underestimated dynamical mass, the baryon fractions measured at z ∼ 6 with JWST are in good agreement with the simulated galaxies.
Paper: An Early Dark Matter–dominated Phase in the Assembly History of Milky Way–mass Galaxies Suggested by the TNG50 Simulation and JWST Observations
Authors: Anna de Graaff, Annalisa Pillepich, Hans-Walter Rix
Figure caption: Mass assembly histories of low-mass TNG50 galaxies, selected to have 108 M ⊙ < M * < 109 M ⊙ at z = 6. Although all z = 6 galaxies are selected to be central galaxies in their dark matter haloes, many systems merge to form massive central galaxies or massive satellites in groups and clusters at lower redshifts. To construct the median mass history (solid black lines), we consider only unique subhaloes in each snapshot. The median stellar mass of the z = 6 descendant population increases hundredfold by z = 2; at z = 0 the median stellar mass of the population equals that of the Milky Way but with large scatter (0.6 dex). In orange we show the mass assembly histories (median and 5–95 percentiles) for the population of TNG50 MW and M31 analogs from Pillepich et al. (2023), which were selected as analogs not only by stellar mass but also by environment and stellar morphology. We find that 50 out of 213 galaxies of the z = 6 descendant population are indeed MW or M31 analogs at z = 0.
Paper: An Early Dark Matter–dominated Phase in the Assembly History of Milky Way–mass Galaxies Suggested by the TNG50 Simulation and JWST Observations
Authors: Anna de Graaff, Annalisa Pillepich, Hans-Walter Rix
Figure caption: Evolution in the baryonic mass fraction (left) and stellar-to-gas mass ratio (right) within a fixed spherical aperture of radius 1 kpc according to the IllustrisTNG and EAGLE cosmological hydrodynamical galaxy simulations. Colored lines show the median f baryon and M */M gas ratio within narrow stellar mass ranges for central galaxies in the TNG50 (dashed) and TNG100 (dashed–dotted) simulations and, for comparison, also the EAGLE Ref-L100N1504 simulation (dotted). Solid black lines show the median time evolution of the descendant population of low-mass (M * ∼ 108−9 M ⊙) galaxies selected from TNG50 at z = 6, with shaded regions indicating the 16th–84th and 5th–95th percentiles. As the z = 6 galaxies grow in stellar mass, f baryon and M */M gas increase rapidly, resulting in stellar mass–dominated centers by z ∼ 2.
Paper: The Potential of Asteroseismology to Resolve the Blue Supergiant Problem
Authors: Earl Patrick Bellinger, Selma E. de Mink, Walter E. van Rossem, Stephen Justham
Figure caption: Propagation diagram showing the buoyancy (N) and Lamb (S  ℓ=1) frequency profiles (Equation (3)), which determine the asteroseismic characteristics, as a function of fractional mass (left panels) and fractional radius (right panels) for stellar models of 17 M ⊙ and 35 R ⊙. The buoyancy frequency is imaginary in convective zones and hence shows, for example in the merger model the convective He-burning core, intermediate convection zone above the H-burning shell, and two subsurface convection zones. The overlap of the p- and g-mode cavities in the near-surface layers causes most of the dipole modes to be mixed modes. The extended MS stars have higher ΔΠ (here 170 min, rather than 30 min for the other models) because of their larger ∫N/r dr.
Paper: The Potential of Asteroseismology to Resolve the Blue Supergiant Problem
Authors: Earl Patrick Bellinger, Selma E. de Mink, Walter E. van Rossem, Stephen Justham
Figure caption: Kippenhahn diagrams showing the evolution of stars through the BSG phase, all with an initial mass of 17 M ⊙. The classical HG star is short lived (0.01 Myr, upper left panel), while the other solutions are all long lived. Convective regions are shown in gray; g-modes are exponentially damped in these regions. Regions of nuclear fusion are indicated by slashes. The buoyancy frequency is given in green; a sharp peak is visible below the H-burning shell of the merger model. The photosphere of each model is colored by the spectral type. Contours of constant radius are shown for 1, 10, and 35 R ⊙, the latter of which is the approximate radius of a BSG in this mass range. The black star above the photosphere in each diagram indicates which BSG model is further visualized in Figure 5. For an example of how to read these diagrams, the classical HG star is shown passing from having an H-burning core into a brief phase as a BSG with a H-burning shell for ∼10 kyr, followed by entering the red supergiant phase with a large convective envelope, a He-burning core, and an H-burning shell.