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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. The end of BSAX GRB activities
  2. GRB 020410, Radio Observations
  3. GRB 020418: Optical observations
  4. GRB 020124: Optical observations
  5. GRB 020418: Optical observations
  6. IPN triangulation of GRB020418
  7. GRB020405: VLT observations of the OT environment
  8. GRB020410: BeppoSAX NFI observations refined analysis
  9. GRB 020409: Optical Observations
  10. Mars Odyssey joins the IPN
  11. IPN triangulation of GRB020413
  12. GRB 020409, 2-nd epoch optical observations at Terskol.
  13. GRB020405: predicted break
  14. GRB 020409: Optical observations
  15. GRB 020409, No Optical Detection to R = 22
  16. GRB020410: second BeppoSAX NFI observation
  17. GRB 020409: No Evidence for an Optical Afterglow
  18. GRB 020409, 2nd epoch optical observations
  19. GRB 020331 Kyoto observation on March 31
  20. GRB 020409
  21. GRB 020409 SARA Observations
  22. GRB "020411"
  23. GRB 020409, No Optical Detection to R = 20
  24. GRB020410: BeppoSAX NFI observation
  25. GRB 020409: Optical observations
  26. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  27. GRB 020410, optical observations
  28. BeppoSAX ALERT: possible GRB020411
  29. GRB 020409, optical observations
  30. GRB 020409: Optical Observations
  31. GRB020406(?), optical observations
  32. GRB020410, optical observations
  33. BeppoSAX ALERT: possible GRB020410
  34. X-ray afterglow of GRB020321
  35. BeppoSAX GRB : GRB020409
  36. GRB020331: Confirmation of Afterglow Candidate with Magellan
  37. GRB020405: VLT optical observations and V band decay slope
  38. GRB020331 optical observations with RIMOTS
  39. GRB020124 optical observations with RIBOTS/RIMOTS
  40. GRB 020321: Candidate X-ray Counterparts
  41. ASM GRB candidate 020406 refined error box
  42. GRB 020405: Moderate-resolution spectroscopy
  43. GRB020331: Optical Observations of Afterglow Candidate
  44. GRB020406(?), optical observations
  45. GRB020405: VLT optical observations
  46. Revised Photometry of the Optical Afterglow of GRB 020405
  47. GRB020405: OT observations
  48. GRB 020331: Candidate Optical Afterglow
  49. GRB 020405: Decay index
  50. Short RXTE/ASM transient 020406; may be a GRB
  51. GRB020405, Radio Observations
  52. GRB020405: VLT spectroscopy
  53. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  54. V band observations of GRB020405
  55. GRB 020405, U-band observations
  56. GRB 020405: Optical afterglow candidate
  57. IPN localization of GRB020405
  58. GRB011212: Optical Observations
  59. GRB 020331: NIR Observations
  60. GRB 020331: NIR Observations
  61. GRB020331 NIR observation at KPNO (re-submission)
  62. GRB02033 NIR observation at KPNO
  63. GRB020331 field photometry
  64. GRB 020331 Optical Observations
  65. GRB 020331, NIR observations
  66. GRB 020331: Optical observations
  67. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  68. GRB 020321: Infrared observations
  69. GRB 020322: BeppoSAX observations of the X-ray afterglow
  70. SN 2002ap - peak brightness date (SN/GRB?)
  71. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  72. GRB 020322, Radio observations
  73. Near-Infrared Observations of GRB020322 at TIRGO
  74. GRB 020321, Radio Observations
  75. GRB 020322: Optical Observations
  76. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  77. GRB 020321: Optical observations
  78. GRB020317 BVRI field photometry
  79. GRB011211 revised BVRI field photometry
  80. GRB020305 BVRI field photometry
  81. GRB020322 BVRI field photometry
  82. GRB 020322 optical observations
  83. GRB020322: Candidate Optical Afterglow
  84. GRB 020322 optical observation
  85. GRB020317 : Near IR Observations from Mt Abu Observatory
  86. GRB 020322: Optical Sources and Improved Astrometry
  87. GRB020322, optical observations
  88. GRB 020322: Optical candidate
  89. XMM-Newton observation of GRB020322
  90. GRB020322: Optical Observations
  91. GRB020322: BeppoSAX/NFI Observations
  92. Bepposax GRB020322 The second springtime BSAX GRB
  93. GRB 020321: Optical observations
  94. GRB 011121: Fourth Epoch of HST Imaging
  95. GRB020317: optical observations
  96. GRB020321 optical observations
  97. GRB020321: BeppoSAX/NFI Observations
  98. GRB020321: a faint BeppoSAX detection
  99. GRB020305: NIR observations
  100. GRB 020317 : KISO Optical Observations

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