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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

25042 results found.

  1. SGR-like Bursts from the AXP 1E 2259+586
  2. GRB020405: polarimetric observations
  3. GRB 020531, simultaneous optical observations
  4. GRB 020531/Candidate Redshift
  5. GRB020531: Detection of Candidate Host Galaxy
  6. GRB020531: Second epoch Chandra observations
  7. GRB020604, optical observations
  8. GRB020604, BVRcIc field photometry
  9. GRB020603, BVRcIc field observations
  10. GRB020531, BVRcIc field photometry
  11. GRB020531 Optical Observations
  12. GRB020531: Observations with the Chandra X-ray Observatory
  13. GRB020531, optical observations
  14. GRB020531: optical observations
  15. GRB020531(=H2042): Optical Observations
  16. GRB020531(=H2042): Optical Observations
  17. GRB020531: Optical observations
  18. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  19. GRB020525, optical observations
  20. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  21. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  22. HST detection of the likely host galaxy of GRB 020124
  23. GRB020405 field photometry at ESO
  24. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  25. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  26. GRB020321 : Optical observations.
  27. XRF 020427
  28. GRB 020124: Optical observations
  29. IPN triangulation of GRB020418
  30. GRB020405: VLT observations of the OT environment
  31. IPN triangulation of GRB020413
  32. GRB020405: predicted break
  33. GRB 020409: No Evidence for an Optical Afterglow
  34. GRB 020331 Kyoto observation on March 31
  35. GRB020410: BeppoSAX NFI observation
  36. X-ray afterglow of GRB020321
  37. GRB020331 optical observations with RIMOTS
  38. GRB020124 optical observations with RIBOTS/RIMOTS
  39. GRB 020321: Candidate X-ray Counterparts
  40. GRB020406(?), optical observations
  41. GRB 020405: Decay index
  42. Short RXTE/ASM transient 020406; may be a GRB
  43. GRB020405, Radio Observations
  44. GRB 020405, U-band observations
  45. GRB011212: Optical Observations
  46. GRB 020331: NIR Observations
  47. GRB020331 NIR observation at KPNO (re-submission)
  48. GRB02033 NIR observation at KPNO
  49. GRB020331 field photometry
  50. GRB 020331, NIR observations
  51. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  52. GRB 020322: BeppoSAX observations of the X-ray afterglow
  53. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  54. Near-Infrared Observations of GRB020322 at TIRGO
  55. GRB 020321, Radio Observations
  56. GRB 020322: Optical Observations
  57. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  58. GRB 020321: Optical observations
  59. GRB020317 BVRI field photometry
  60. GRB011211 revised BVRI field photometry
  61. GRB020305 BVRI field photometry
  62. GRB020322 BVRI field photometry
  63. GRB 020322: Optical Sources and Improved Astrometry
  64. GRB020317: optical observations
  65. GRB020321 optical observations
  66. GRB020321: a faint BeppoSAX detection
  67. GRB 020317 : KISO Optical Observations
  68. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  69. GRB 020305: Optical Observations
  70. GRB020317, optical observations
  71. GRB 020317: Optical observations
  72. GRB 011121: Third HST Epoch
  73. GRB020305: Properties of the Candidate Optical Afterglow
  74. GRB 011121: HST Observations reveal an intermediate-time multicolor
  75. GRB011130 (XRF011130) Second Epoch Chandra Observations
  76. GRB020305: Subaru Optical Observations
  77. XRF/GRB 011030: Detection of the Probable Host Galaxy
  78. GRB 020305: Candidate optical afterglow
  79. GRB020305, optical observations
  80. IPN triangulation of GRB020305 (HETE 1939)
  81. GRB020305 (=H1939): Localization of a GRB by HETE
  82. HST Imaging of the afterglow and host of GRB 011121
  83. IPN detection and localization of Cygnus X-1 flares
  84. SGR1900+14 activity
  85. IPN Upper Limits to a GRB Associated With SN2002ap
  86. GRB020124 BVRI field photometry
  87. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  88. SN2002ap (SN/GRB?) Echelle spectra
  89. GRB020127 Optical Observations
  90. SN 2002ap in M74
  91. SN2002ap (SN/GRB?) UBVRI Field Photometry
  92. GRB020127: Chandra Observations and Prospective Counterparts
  93. pre-SN2002ap (SN/GRB?) imaging of M74
  94. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  95. GRB020124, optical observations
  96. GRB 020127, I-band observations starting 3.14-hr after the event
  97. GRB010921 Optical Observations
  98. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  99. GRB020124: Optical observations
  100. GRB 020124: Optical observations

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