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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. GRB 020409
  2. GRB 020409 SARA Observations
  3. GRB "020411"
  4. GRB 020409, No Optical Detection to R = 20
  5. GRB020410: BeppoSAX NFI observation
  6. GRB 020409: Optical observations
  7. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  8. GRB 020410, optical observations
  9. BeppoSAX ALERT: possible GRB020411
  10. GRB 020409, optical observations
  11. GRB 020409: Optical Observations
  12. GRB020406(?), optical observations
  13. GRB020410, optical observations
  14. BeppoSAX ALERT: possible GRB020410
  15. X-ray afterglow of GRB020321
  16. BeppoSAX GRB : GRB020409
  17. GRB020331: Confirmation of Afterglow Candidate with Magellan
  18. GRB020405: VLT optical observations and V band decay slope
  19. GRB020331 optical observations with RIMOTS
  20. GRB020124 optical observations with RIBOTS/RIMOTS
  21. GRB 020321: Candidate X-ray Counterparts
  22. ASM GRB candidate 020406 refined error box
  23. GRB 020405: Moderate-resolution spectroscopy
  24. GRB020331: Optical Observations of Afterglow Candidate
  25. GRB020406(?), optical observations
  26. GRB020405: VLT optical observations
  27. Revised Photometry of the Optical Afterglow of GRB 020405
  28. GRB020405: OT observations
  29. GRB 020331: Candidate Optical Afterglow
  30. GRB 020405: Decay index
  31. Short RXTE/ASM transient 020406; may be a GRB
  32. GRB020405, Radio Observations
  33. GRB020405: VLT spectroscopy
  34. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  35. V band observations of GRB020405
  36. GRB 020405, U-band observations
  37. GRB 020405: Optical afterglow candidate
  38. IPN localization of GRB020405
  39. GRB011212: Optical Observations
  40. GRB 020331: NIR Observations
  41. GRB 020331: NIR Observations
  42. GRB020331 NIR observation at KPNO (re-submission)
  43. GRB02033 NIR observation at KPNO
  44. GRB020331 field photometry
  45. GRB 020331 Optical Observations
  46. GRB 020331, NIR observations
  47. GRB 020331: Optical observations
  48. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  49. GRB 020321: Infrared observations
  50. GRB 020322: BeppoSAX observations of the X-ray afterglow
  51. SN 2002ap - peak brightness date (SN/GRB?)
  52. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  53. GRB 020322, Radio observations
  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 observations
  64. GRB020322: Candidate Optical Afterglow
  65. GRB 020322 optical observation
  66. GRB020317 : Near IR Observations from Mt Abu Observatory
  67. GRB 020322: Optical Sources and Improved Astrometry
  68. GRB020322, optical observations
  69. GRB 020322: Optical candidate
  70. XMM-Newton observation of GRB020322
  71. GRB020322: Optical Observations
  72. GRB020322: BeppoSAX/NFI Observations
  73. Bepposax GRB020322 The second springtime BSAX GRB
  74. GRB 020321: Optical observations
  75. GRB 011121: Fourth Epoch of HST Imaging
  76. GRB020317: optical observations
  77. GRB020321 optical observations
  78. GRB020321: BeppoSAX/NFI Observations
  79. GRB020321: a faint BeppoSAX detection
  80. GRB020305: NIR observations
  81. GRB 020317 : KISO Optical Observations
  82. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  83. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  84. GRB 020305: Optical Observations
  85. GRB020317, optical observations
  86. GRB 020317: Optical observations
  87. GRB 011121: Third HST Epoch
  88. GRB020305: Properties of the Candidate Optical Afterglow
  89. GRB 011121: HST Observations reveal an intermediate-time multicolor
  90. GRB011121, possible supernova association
  91. GRB011130 (XRF011130) Second Epoch Chandra Observations
  92. GRB020305: Subaru Optical Observations
  93. GRB 020305: Optical observations
  94. XRF/GRB 011030 Images
  95. XRF/GRB 011030: Detection of the Probable Host Galaxy
  96. GRB 020305: Candidate optical afterglow
  97. Type Ic SN2002bl (SN/GRB?) Radio Observations
  98. GRB020305, optical observations
  99. GRB020305: Optical Observations
  100. IPN triangulation of GRB020305 (HETE 1939)

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