The unusual optical afterglow of the gamma-ray burst GRB 021004: Color changes and short-time-scale variability

Abstract

We report UBVRI observations of the optical afterglow of the gamma-ray burst GRB 021004. We observed significant (10-20%) deviations from a power law decay on several time scales, ranging from a few hours down to 20-30 minutes. We also observed a significant color change starting ~1.5 days after the burst, confirming the spectroscopic results already reported by Matheson et al. (2002). We discuss these results in the context of several models that have recently been proposed to account for the anomalous photometric behavior of this event.

arXiv commentSubmitted to ApJL, 14 pages, 4 figures. Data available on anonymous ftp at ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB021004

References in corpus (16)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• A method for optimal image subtraction
• The afterglow of GRB 021004: surfing on density waves
• BVRI Observations of the Optical Afterglow of GRB 990510
• Discovery of the Low-Redshift Optical Afterglow of GRB 011121 and Its Progenitor Supernova 2001ke
• GRB 021004: Reverse Shock Emission
• The Detectability of Orphan Afterglows
• The radio to X-ray spectrum of GRB 970508 on May 21.0 UT
• Absorption Systems in the Spectrum of GRB 021004
• Resolving Gamma-Ray Burst 000301C with a Gravitational Microlens
• Variability of GRB Afterglows Due to Interstellar Turbulence
• The Optical Afterglows of Gamma-Ray Bursts
• The Optical Afterglow of GRB 011211
• The Near Infrared and Multiwavelength Afterglow of GRB 000301c
• Rapid UBVRI Follow-up of the Highly Collimated Optical Afterglow of GRB010222
• The Spectroscopic Variability of GRB 021004

Cited by in corpus (50)

• GRB Energetics and the GRB Hubble Diagram: Promises and Limitations
• Photometry and Spectroscopy of GRB 030329 and Its Associated Supernova 2003dh: The First Two Months
• Variabilities of Gamma-Ray Burst Afterglows: Long-acting Engine, Anisotropic Jet or Many Fluctuating Regions?
• Gamma Ray Bursts as standard candles to constrain the cosmological parameters
• The detailed optical light curve of GRB 030329
• The line-of-sight towards GRB 030429 at z = 2.66: Probing the matter at stellar, galactic and intergalactic scales
• Smooth Light Curves from a Bumpy Ride: Relativistic Blast Wave Encounters a Density Jump
• Ly-alpha and UV emission from high-redshift GRB hosts: To what extent do GRBs trace star formation?
• GRB 021004: A Possible Shell Nebula around a Wolf-Rayet Star Gamma-Ray Burst Progenitor
• The Redshift Distribution of Type-Ia Supernovae: Constraints on Progenitors and Cosmic Star Formation History
• Probing a GRB progenitor at a redshift of z=2: a comprehensive observing campaign of the afterglow of GRB 030226
• The clustering of the luminosities of optical afterglows of long Gamma Ray Bursts
• Detailed optical and near-infrared polarimetry, spectroscopy and broadband photometry of the afterglow of GRB 091018: Polarisation evolution
• Deep Photometry of GRB 041006 Afterglow: Hypernova Bump at Redshift z=0.716
• Fast optical variability of Naked-Eye Burst - manifestation of periodic activity of internal engine
• GRB 021004 modelled by multiple energy injections
• "Anomalous" Optical GRB Afterglows are Common: Two z~4 Bursts, GRB 060206 and 060210
• Variable polarization in the optical afterglow of GRB 021004
• Spectroscopy of GRB 021004: a structured jet ploughing through a massive stellar wind
• Optical and X-Ray Observations of GRB 060526: A Complex Afterglow Consistent with An Achromatic Jet Break
• High Quality Early Time Light Curves of GRB 060206: Implications for Gamma Ray Burst Environments and Energetics
• On the absence of Wind Signatures in GRB Afterglow Spectra: Constraints on the Wolf-Rayet Winds of GRB Progenitors
• Polarization and light curve variability: the "patchy shell" model
• On the Afterglow and Host Galaxy of GRB021004: A Comprehensive Study with the Hubble Space Telescope
• Intrinsic and dust-induced polarization in gamma-ray burst afterglows: the case of GRB 021004
• Broadband Modeling of GRB 021004
• Modeling Fluctuations in the GRB-Afterglow Light Curves
• GRB 021004: Tomography of a gamma-ray burst progenitor and its host galaxy
• Wind-Interaction Models for the Early Afterglows of Gamma-Ray Bursts: The Case of GRB 021004
• When Do Internal Shocks End and External Shocks Begin? Early-Time Broadband Modelling of GRB 051111
• Small-scale variations in the radiating surface of the GRB 011211 jet
• The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB 070125
• Disparate MgII Absorption Statistics towards Quasars and Gamma-Ray Bursts : A Possible Explanation
• GRB 021211 as a Faint Analogue of GRB 990123: Exploring the Similarities and Differences in their Optical Afterglows
• High-Precision Photometry of the Gamma-Ray Burst 020813: The Smoothest Afterglow Yet
• Go Long, Go Deep: Finding Optical Jet Breaks for Swift-Era GRBs with the LBT
• An Estimation of the Gamma-Ray Burst Afterglow Apparent Optical Brightness Distribution Function
• SCUBA sub-millimeter observations of gamma-ray bursters IV. GRB 021004, 021211, 030115, 030226, 041006
• The variable X-ray light curve of GRB 050713A: the case of refreshed shocks
• Optical observations of GRB 060124 afterglow: A case for an injection break
• Revealing the Jet Structure of GRB 030329 with High Resolution Multicolor Photometry
• What we learn from the afterglow of GRB 021211
• Investigating the impact of optical selection effects on observed rest frame prompt GRB properties
• Searching for Fast Optical Transients using VERITAS Cherenkov Telescopes
• Core-collapse Supernovae and Gamma-ray Bursts in TMT Era
• HETE-2 Observations of the X-Ray Flash XRF 040916
• The Synoptic Swift Synergy -- Catching Gamma-Ray Bursts Before They Fly
• Multi-epoch afterglow rebrightenings in GRB 250129A: Evidence for successive shock interactions
• The Liverpool Telescope: Rapid follow-up observation of Targets of opportunity with a 2 m robotic telescope
• On the Variability of Gamma-Ray Burst Afterglows - A Possibility of a Transition to Nonrelativistic Motion