SN 2021hpr: A Normal Type Ia Supernova Showing Excess Emission in the Early Rising Phase

Abstract

We present extensive optical observations of a nearby Type Ia supernova (SN Ia), SN 2021hpr, located in the spiral galaxy NGC 3147 at a distance of $\sim$ 45 Mpc. Our observations cover a phase within $\sim 1-2$ days to $\sim 290$ days after the explosion. SN 2021hpr is found to be a spectroscopically normal SN Ia, with an absolute B-band peak magnitude of $M_{max}(B)\approx -19.16\pm 0.14$ mag and a post-peak decline rate of $\Delta m_{15}(B)=1.00\pm 0.01$ mag. Early-time light curves showed a $\sim 7.0\%$ excess emission compared to a homogeneously expanding fireball model, likely due to SN ejecta interacting with a companion or immediate circumstellar matter. The optical spectra of SN 2021hpr are overall similar to those of normal SNe Ia, but characterized by prominent detached high-velocity features (HVFs) of Si {\sc ii} and Ca {\sc ii} in the early phase. After examining a small sample of well-observed normal SNe Ia, we find that the HVFs are likely common for the subgroup with early-excess emission. The association of early bump feature with the HVFs could be attributed to density or abundance enhancement at the outer layer of the exploding star, likely as a result of interactions with companion$/$CSM or experiencing more complete burning. Nevertheless, the redshifted Fe {\sc ii} and Ni {\sc ii} lines in the nebular-phase spectra of SN 2021hpr, contrary to the blueshift trend seen in other SNe Ia showing early bump features, indicate its peculiarity in the explosion that remains to be understood.

arXiv comment27 pages, 15 figures, Accepted for publication in ApJ

References in corpus (114)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• emcee: The MCMC Hammer
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Las Cumbres Observatory Global Telescope Network
• The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)
• The Pan-STARRS1 Photometric System
• Observational clues to the progenitors of Type-Ia supernovae
• Nearby Supernova Rates from the Lick Observatory Supernova Search. II. The Observed Luminosity Functions and Fractions of Supernovae in a Complete Sample
• The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae
• A Precise Distance Indicator: Type Ia Supernova Multicolor Light Curve Shapes
• Three-dimensional delayed-detonation models with nucleosynthesis for Type Ia supernovae
• Supernova 2011fe from an Exploding Carbon-Oxygen White Dwarf Star
• Normal Type Ia supernovae from violent mergers of white dwarf binaries
• Seeing the Collision of a Supernova with its Companion Star
• Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries
• Sub-luminous type Ia supernovae from the mergers of equal-mass white dwarfs with M~0.9 M_sun
• Type Iax Supernovae: A New Class of Stellar Explosion
• The diversity of Type Ia Supernovae: evidence for systematics?
• Progenitors of type Ia supernovae
• Evidence for a Spectroscopic Sequence Among SNe Ia
• UBVRI Light Curves of 44 Type Ia Supernovae
• The diversity of Type II supernova versus the similarity in their progenitors
• SN 2002cx: The Most Peculiar Known Type Ia Supernova
• PTF11kx: A Type-Ia Supernova with a Symbiotic Nova Progenitor
• Generalized Semi-Analytical Models of Supernova Light Curves
• Constraints on the Progenitor System of the Type Ia Supernova SN 2011fe/PTF11kly
• The Carnegie Supernova Project: Light Curve Fitting with SNooPy
• A Compact Degenerate Primary-Star Progenitor of SN 2011fe
• Improved Distances to Type Ia Supernovae with Two Spectroscopic Subclasses
• The ATLAS All-Sky Stellar Reference Catalog
• Head-on collisions of white dwarfs in triple systems could explain type Ia supernova
• Analytical Light Curve Models of Super-Luminous Supernovae: chi^2-Minimizations of Parameter Fits
• Sub-Chandrasekhar-mass white dwarf detonations revisited
• The Risetime of Nearby Type Ia Supernovae
• SiFTO: An Empirical Method for Fitting SNe Ia Light Curves
• The Carnegie Supernova Project: Intrinsic Colors of Type Ia Supernovae
• Type Ia Supernovae Strongly Interacting with Their Circumstellar Medium
• Spectrophotometric time series of SN 2011fe from the Nearby Supernova Factory
• Helium star donor channel for the progenitors of type Ia supernovae
• Supernova 2002bo: inadequacy of the single parameter description
• Strong Ultraviolet Pulse From a Newborn Type Ia Supernova
• A New Cepheid Distance to the Giant Spiral M101 Based On Image Subtraction of HST/ACS Observations
• The Carnegie Supernova Project: Absolute Calibration and the Hubble Constant
• Observational Predictions for Sub-Chandrasekhar Mass Explosions: Further Evidence for Multiple Progenitor Systems for Type Ia Supernovae
• Evidence for Two Distinct Populations of Type Ia Supernovae
• GHASP : An Halpha kinematic survey of spiral and irregular galaxies - VI. New Halpha data cubes for 108 galaxies
• A Golden Standard Type Ia Supernova SN 2005cf: Observations from the Ultraviolet to the Near-Infrared Wavebands
• Nucleosynthesis in Two-Dimensional Delayed Detonation Models of Type Ia Supernova Explosions
• The Xinglong 2.16-m Telescope: Current Instruments and Scientific Projects
• The Extremes of Thermonuclear Supernovae
• Observational Properties of Thermonuclear Supernovae
• SN~2012cg: Evidence for Interaction Between a Normal Type Ia Supernova and a Non-Degenerate Binary Companion
• Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor
• SN 2003du: Signatures of the Circumstellar Environment in a Normal Type Ia Supernova?
• A hybrid type Ia supernova with an early flash triggered by helium-shell detonation
• The Katzman Automatic Imaging Telescope Gamma-Ray Burst Alert System, and Observations of GRB 020813
• Exploring the Potential Diversity of Early Type Ia Supernova Light Curves
• BVRI lightcurves of supernovae SN 2011fe in M101, SN 2012aw in M95, and SN 2012cg in NGC 4424
• A statistical analysis of circumstellar material in Type Ia supernovae
• Lijiang 2.4-meter Telescope and its Instruments
• The Very Young Type Ia Supernova 2013dy: Discovery, and Strong Carbon Absorption in Early-Time Spectra
• Optical Observations of the Type Ia Supernova 2011fe in M101 for Nearly 500 Days
• Berkeley Supernova Ia Program II: Initial Analysis of Spectra Obtained Near Maximum Brightness
• Optical and IR observations of SN 2002dj: some possible common properties of fast expanding SNe Ia
• Early light curves for Type Ia supernova explosion models
• Seeing Double: ASASSN-18bt Exhibits a Two-Component Rise in the Early-Time K2 Light Curve
• Using late-time optical and near-infrared spectra to constrain Type Ia supernova explosion properties
• Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations
• Searching for swept-up Hydrogen and Helium in the late-time spectra of 11 nearby Type Ia supernovae
• Lick Observatory Supernova Search Follow-Up Program: Photometry Data Release of 93 Type Ia Supernovae
• A Novel Color Parameter As A Luminosity Calibrator for Type Ia Supernovae
• A Shock Flash Breaking Out of a Dusty Red Supergiant
• Constraints on Type Ia Supernova Progenitor Companions from Early Ultraviolet Observations with Swift
• A remarkable recurrent nova in M31 - The optical observations
• Nebular Spectra of 111 Type Ia Supernovae Disfavor Single Degenerate Progenitors
• 500 Days of SN 2013dy: spectra and photometry from the ultraviolet to the infrared
• Nebular Spectroscopy of the `Blue Bump' Type Ia Supernova 2017cbv
• Determining the ${}^{56}$Ni distribution of type Ia supernovae from observations within days of explosion
• Probing type Ia supernova properties using bolometric light curves from the Carnegie Supernova Project and the CfA Supernova Group
• No Stripped Companion Material in the Nebular Spectrum of the "Two-Component" Type Ia Supernova ASASSN-18bt
• Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment
• Early observations of the nearby type Ia supernova SN 2015F
• An investigation of ${}^{56}$Ni shells as the source of early light curve bumps in type Ia supernovae
• The Young and Nearby Normal Type Ia Supernova 2018gv: UV-Optical Observations and the Earliest Spectropolarimetry
• The Silicon and Calcium High-Velocity Features in Type Ia Supernovae from Early to Maximum Phases
• Berkeley Supernova Ia Program: Data Release of 637 Spectra from 247 Type Ia Supernovae
• Nebular Spectroscopy of Kepler's Brightest Supernova
• A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone can Explain Early-Excess Blue Flux in Some Type Ia Supernovae
• Stable nickel production in Type Ia supernovae: A smoking gun for the progenitor mass?
• Red and Reddened: Ultraviolet through Near-Infrared Observations of Type Ia Supernova 2017erp
• Progressive Red Shifts in the Late-Time Spectra of Type Ia Supernovae
• The Oxygen Features in Type Ia Supernovae and the Implications for the Nature of Thermonuclear Explosions
• Explaining the early excess emission of the Type Ia supernova 2018oh by the interaction of the ejecta with disk-originated matter (DOM)
• Observations of the Very Young Type Ia Supernova 2019np with Early-excess Emission
• The first 48: Discovery and progenitor constraints on the Type Ia supernova 2013gy
• Early Spectral Evolution of the Rapidly Expanding Type Ia SN 2006X
• Multi-layered Spectral Formation in SNe Ia Around Maximum Light
• The Night Sky Spectrum of Xinglong Observatory: Changes from 2004 to 2015
• An Empirical Fitting Method for Type Ia Supernova Light Curves. II. Estimating the First-Light Time and Rise Time
• Optical and Near-Infrared Observations of the Nearby Type Ia Supernova 2017cbv
• The Wide-field Photometric System of the Nanshan One-meter Telescope
• The Early Light Curve of SN 2023bee: Constraining Type Ia Supernova Progenitors the Apian Way
• Nebular-Phase Spectra of Type Ia Supernovae from the Las Cumbres Observatory Global Supernova Project
• The detection efficiency of type Ia supernovae from the Zwicky Transient Facility: Limits on the intrinsic rate of early flux excesses
• Origin of high-velocity ejecta and early red excess emission in the infant Type Ia supernova 2021aefx
• Optical and Infrared Photometry of the Nearby SN 2017cbv
• The Early Light Curve of a Type Ia Supernova 2021hpr in NGC 3147: Progenitor Constraints with the Companion Interaction Model
• Optical Observations of the Nearby Type Ia Supernova 2021hpr
• SN 2017hpa: A Nearby Carbon-Rich Type Ia Supernova with a Large Velocity Gradient
• Possible Circumstellar Interaction Origin of the Early Excess Emission in Thermonuclear Supernovae
• Three is the magic number -- distance measurement of NGC 3147 using SN 2021hpr and its siblings
• The LCOGT Network
• Stellar evolution, SN explosion, and nucleosynthesis