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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"

24610 results found.

  1. GRB 020409: No Evidence for an Optical Afterglow
  2. GRB 020331 Kyoto observation on March 31
  3. GRB020410: BeppoSAX NFI observation
  4. X-ray afterglow of GRB020321
  5. GRB020331 optical observations with RIMOTS
  6. GRB020124 optical observations with RIBOTS/RIMOTS
  7. GRB 020321: Candidate X-ray Counterparts
  8. GRB020406(?), optical observations
  9. GRB 020405: Decay index
  10. Short RXTE/ASM transient 020406; may be a GRB
  11. GRB020405, Radio Observations
  12. GRB 020405, U-band observations
  13. GRB011212: Optical Observations
  14. GRB 020331: NIR Observations
  15. GRB020331 NIR observation at KPNO (re-submission)
  16. GRB02033 NIR observation at KPNO
  17. GRB020331 field photometry
  18. GRB 020331, NIR observations
  19. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  20. GRB 020322: BeppoSAX observations of the X-ray afterglow
  21. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  22. Near-Infrared Observations of GRB020322 at TIRGO
  23. GRB 020321, Radio Observations
  24. GRB 020322: Optical Observations
  25. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  26. GRB 020321: Optical observations
  27. GRB020317 BVRI field photometry
  28. GRB011211 revised BVRI field photometry
  29. GRB020305 BVRI field photometry
  30. GRB020322 BVRI field photometry
  31. GRB 020322: Optical Sources and Improved Astrometry
  32. GRB020317: optical observations
  33. GRB020321 optical observations
  34. GRB020321: a faint BeppoSAX detection
  35. GRB 020317 : KISO Optical Observations
  36. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  37. GRB 020305: Optical Observations
  38. GRB020317, optical observations
  39. GRB 020317: Optical observations
  40. GRB 011121: Third HST Epoch
  41. GRB020305: Properties of the Candidate Optical Afterglow
  42. GRB 011121: HST Observations reveal an intermediate-time multicolor
  43. GRB011130 (XRF011130) Second Epoch Chandra Observations
  44. GRB020305: Subaru Optical Observations
  45. XRF/GRB 011030: Detection of the Probable Host Galaxy
  46. GRB 020305: Candidate optical afterglow
  47. GRB020305, optical observations
  48. IPN triangulation of GRB020305 (HETE 1939)
  49. GRB020305 (=H1939): Localization of a GRB by HETE
  50. HST Imaging of the afterglow and host of GRB 011121
  51. IPN detection and localization of Cygnus X-1 flares
  52. SGR1900+14 activity
  53. IPN Upper Limits to a GRB Associated With SN2002ap
  54. GRB020124 BVRI field photometry
  55. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  56. SN2002ap (SN/GRB?) Echelle spectra
  57. GRB020127 Optical Observations
  58. SN 2002ap in M74
  59. SN2002ap (SN/GRB?) UBVRI Field Photometry
  60. GRB020127: Chandra Observations and Prospective Counterparts
  61. pre-SN2002ap (SN/GRB?) imaging of M74
  62. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  63. GRB020124, optical observations
  64. GRB 020127, I-band observations starting 3.14-hr after the event
  65. GRB010921 Optical Observations
  66. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  67. GRB020124: Optical observations
  68. GRB 020124: Optical observations
  69. GRB 020124: Optical afterglow
  70. GRB020124(=H1896): Localization of a Long GRB by HETE
  71. Possible optical counterpart to a GRB
  72. GRB011212, Optical Observations
  73. Optical polarization observations for GRB011211
  74. GRB 011211: Detection of the Probable Host Galaxy
  75. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  76. GRB 011130: Optical Observations of X-ray and Radio Sources
  77. GRB 011212: optical observation at Asiago
  78. GRB 011211: Evidence for an Optical Break
  79. GRB 011211: TNG Spectroscopic Observations
  80. optical follow-up of GRB(XRF) 011211
  81. GRB 011212: optical observation at Oslo (relayed)
  82. GRB 011211, Optical Observations
  83. GRB011212, BVRI field photometry
  84. GRB011211, BVRI field photometry
  85. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  86. Fading of the optical source associated of XRF 011211
  87. GRB 011211 Optical Observations: Likely Afterglow
  88. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  89. GRB011130 (XRF011130) Chandra Observations
  90. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  91. GRB 011130, K band observations
  92. GRB011130, optical observations
  93. GRB011130 (=XRF011130): Second Revised Localization by HETE
  94. GRB011130 (XRF011130) SDSS PT i-band observations
  95. XRF011130: Infrared Observations
  96. GRB 011121
  97. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  98. GRB 011121: J-band observations
  99. GRB 011121: NIR observations, host galaxy?
  100. GRB011121: UBRI Observations

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