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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. Mars Odyssey joins the IPN
  2. IPN triangulation of GRB020413
  3. GRB 020409, 2-nd epoch optical observations at Terskol.
  4. GRB020405: predicted break
  5. GRB 020409: Optical observations
  6. GRB 020409, No Optical Detection to R = 22
  7. GRB020410: second BeppoSAX NFI observation
  8. GRB 020409: No Evidence for an Optical Afterglow
  9. GRB 020409, 2nd epoch optical observations
  10. GRB 020331 Kyoto observation on March 31
  11. GRB 020409
  12. GRB 020409 SARA Observations
  13. GRB "020411"
  14. GRB 020409, No Optical Detection to R = 20
  15. GRB020410: BeppoSAX NFI observation
  16. GRB 020409: Optical observations
  17. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  18. GRB 020410, optical observations
  19. BeppoSAX ALERT: possible GRB020411
  20. GRB 020409, optical observations
  21. GRB 020409: Optical Observations
  22. GRB020406(?), optical observations
  23. GRB020410, optical observations
  24. BeppoSAX ALERT: possible GRB020410
  25. X-ray afterglow of GRB020321
  26. BeppoSAX GRB : GRB020409
  27. GRB020331: Confirmation of Afterglow Candidate with Magellan
  28. GRB020405: VLT optical observations and V band decay slope
  29. GRB020331 optical observations with RIMOTS
  30. GRB020124 optical observations with RIBOTS/RIMOTS
  31. GRB 020321: Candidate X-ray Counterparts
  32. ASM GRB candidate 020406 refined error box
  33. GRB 020405: Moderate-resolution spectroscopy
  34. GRB020331: Optical Observations of Afterglow Candidate
  35. GRB020406(?), optical observations
  36. GRB020405: VLT optical observations
  37. Revised Photometry of the Optical Afterglow of GRB 020405
  38. GRB020405: OT observations
  39. GRB 020331: Candidate Optical Afterglow
  40. GRB 020405: Decay index
  41. Short RXTE/ASM transient 020406; may be a GRB
  42. GRB020405, Radio Observations
  43. GRB020405: VLT spectroscopy
  44. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  45. V band observations of GRB020405
  46. GRB 020405, U-band observations
  47. GRB 020405: Optical afterglow candidate
  48. IPN localization of GRB020405
  49. GRB011212: Optical Observations
  50. GRB 020331: NIR Observations
  51. GRB 020331: NIR Observations
  52. GRB020331 NIR observation at KPNO (re-submission)
  53. GRB02033 NIR observation at KPNO
  54. GRB020331 field photometry
  55. GRB 020331 Optical Observations
  56. GRB 020331, NIR observations
  57. GRB 020331: Optical observations
  58. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  59. GRB 020321: Infrared observations
  60. GRB 020322: BeppoSAX observations of the X-ray afterglow
  61. SN 2002ap - peak brightness date (SN/GRB?)
  62. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  63. GRB 020322, Radio observations
  64. Near-Infrared Observations of GRB020322 at TIRGO
  65. GRB 020321, Radio Observations
  66. GRB 020322: Optical Observations
  67. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  68. GRB 020321: Optical observations
  69. GRB020317 BVRI field photometry
  70. GRB011211 revised BVRI field photometry
  71. GRB020305 BVRI field photometry
  72. GRB020322 BVRI field photometry
  73. GRB 020322 optical observations
  74. GRB020322: Candidate Optical Afterglow
  75. GRB 020322 optical observation
  76. GRB020317 : Near IR Observations from Mt Abu Observatory
  77. GRB 020322: Optical Sources and Improved Astrometry
  78. GRB020322, optical observations
  79. GRB 020322: Optical candidate
  80. XMM-Newton observation of GRB020322
  81. GRB020322: Optical Observations
  82. GRB020322: BeppoSAX/NFI Observations
  83. Bepposax GRB020322 The second springtime BSAX GRB
  84. GRB 020321: Optical observations
  85. GRB 011121: Fourth Epoch of HST Imaging
  86. GRB020317: optical observations
  87. GRB020321 optical observations
  88. GRB020321: BeppoSAX/NFI Observations
  89. GRB020321: a faint BeppoSAX detection
  90. GRB020305: NIR observations
  91. GRB 020317 : KISO Optical Observations
  92. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  93. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  94. GRB 020305: Optical Observations
  95. GRB020317, optical observations
  96. GRB 020317: Optical observations
  97. GRB 011121: Third HST Epoch
  98. GRB020305: Properties of the Candidate Optical Afterglow
  99. GRB 011121: HST Observations reveal an intermediate-time multicolor
  100. GRB011121, possible supernova association

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