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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. GRB020405: polarimetric observations
  2. GRB 020531, simultaneous optical observations
  3. GRB 020604, 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 with TAROT
  12. GRB020531 Optical observations with TAROT
  13. GRB 020418, optical/near-IR observations
  14. GRB 020531, Radio Observations
  15. IPN triangulation of GRB020604
  16. GRB020531 Optical Observations
  17. GRB020531: Observations with the Chandra X-ray Observatory
  18. GRB 020603: Optical Observations
  19. GRB 020603, R-band observation
  20. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  21. GRB020531: Upper Limit for Detection of Two TAROT Sources
  22. GRB 020603: Optical observations
  23. IPN triangulation of GRB020603 (possible short/hard GRB)
  24. GRB 020531 optical observations with TAROT
  25. Refined IPN error box for GRB020531
  26. GRB020531, optical observations
  27. GRB020531: optical observations
  28. GRB020531, optical observation
  29. GRB020531(=H2042): Optical Observations
  30. IPN triangulation of the short, hard GRB020531 (=H2042)
  31. GRB020531(=H2042): Optical Observations
  32. GRB020531: Optical observations
  33. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  34. GRB 020525: Optical Observations
  35. GRB020525, optical observations
  36. IPN detection of possible bursts from SGR1806-20
  37. IPN triangulation of GRB020525
  38. XRF 020427: Sudden Ionospheric Disturbance (SID)
  39. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  40. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  41. IPN triangulation of a burst from SGR1806-20
  42. GRB/XRF 020427, Radio Observations
  43. HST detection of the likely host galaxy of GRB 020124
  44. GRB020405 field photometry at ESO
  45. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  46. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  47. GRB020321 : Optical observations.
  48. GRB020427 BeppoSAX NFI Observation
  49. XRF 020427
  50. GRB020331: Third Epoch and Revised Second Epoch Optical
  51. The end of BSAX GRB activities
  52. GRB 020410, Radio Observations
  53. GRB 020418: Optical observations
  54. GRB 020124: Optical observations
  55. GRB 020418: Optical observations
  56. IPN triangulation of GRB020418
  57. GRB020405: VLT observations of the OT environment
  58. GRB020410: BeppoSAX NFI observations refined analysis
  59. GRB 020409: Optical Observations
  60. Mars Odyssey joins the IPN
  61. IPN triangulation of GRB020413
  62. GRB 020409, 2-nd epoch optical observations at Terskol.
  63. GRB020405: predicted break
  64. GRB 020409: Optical observations
  65. GRB 020409, No Optical Detection to R = 22
  66. GRB020410: second BeppoSAX NFI observation
  67. GRB 020409: No Evidence for an Optical Afterglow
  68. GRB 020409, 2nd epoch optical observations
  69. GRB 020331 Kyoto observation on March 31
  70. GRB 020409
  71. GRB 020409 SARA Observations
  72. GRB "020411"
  73. GRB 020409, No Optical Detection to R = 20
  74. GRB020410: BeppoSAX NFI observation
  75. GRB 020409: Optical observations
  76. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  77. GRB 020410, optical observations
  78. BeppoSAX ALERT: possible GRB020411
  79. GRB 020409, optical observations
  80. GRB 020409: Optical Observations
  81. GRB020406(?), optical observations
  82. GRB020410, optical observations
  83. BeppoSAX ALERT: possible GRB020410
  84. X-ray afterglow of GRB020321
  85. BeppoSAX GRB : GRB020409
  86. GRB020331: Confirmation of Afterglow Candidate with Magellan
  87. GRB020405: VLT optical observations and V band decay slope
  88. GRB020331 optical observations with RIMOTS
  89. GRB020124 optical observations with RIBOTS/RIMOTS
  90. GRB 020321: Candidate X-ray Counterparts
  91. ASM GRB candidate 020406 refined error box
  92. GRB 020405: Moderate-resolution spectroscopy
  93. GRB020331: Optical Observations of Afterglow Candidate
  94. GRB020406(?), optical observations
  95. GRB020405: VLT optical observations
  96. Revised Photometry of the Optical Afterglow of GRB 020405
  97. GRB020405: OT observations
  98. GRB 020331: Candidate Optical Afterglow
  99. GRB 020405: Decay index
  100. Short RXTE/ASM transient 020406; may be a GRB

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