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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 020531, INT+WFC deep optical upper limits
  2. SGR-like Bursts from the AXP 1E 2259+586
  3. GRB020405: polarimetric observations
  4. GRB 020531, simultaneous optical observations
  5. GRB 020604, optical observations
  6. GRB 020531/Candidate Redshift
  7. GRB020531: Detection of Candidate Host Galaxy
  8. GRB020531: Second epoch Chandra observations
  9. GRB020604, optical observations
  10. GRB020604, BVRcIc field photometry
  11. GRB020603, BVRcIc field observations
  12. GRB020531, BVRcIc field photometry
  13. GRB020531 Optical observations with TAROT
  14. GRB020531 Optical observations with TAROT
  15. GRB 020418, optical/near-IR observations
  16. GRB 020531, Radio Observations
  17. IPN triangulation of GRB020604
  18. GRB020531 Optical Observations
  19. GRB020531: Observations with the Chandra X-ray Observatory
  20. GRB 020603: Optical Observations
  21. GRB 020603, R-band observation
  22. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  23. GRB020531: Upper Limit for Detection of Two TAROT Sources
  24. GRB 020603: Optical observations
  25. IPN triangulation of GRB020603 (possible short/hard GRB)
  26. GRB 020531 optical observations with TAROT
  27. Refined IPN error box for GRB020531
  28. GRB020531, optical observations
  29. GRB020531: optical observations
  30. GRB020531, optical observation
  31. GRB020531(=H2042): Optical Observations
  32. IPN triangulation of the short, hard GRB020531 (=H2042)
  33. GRB020531(=H2042): Optical Observations
  34. GRB020531: Optical observations
  35. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  36. GRB 020525: Optical Observations
  37. GRB020525, optical observations
  38. IPN detection of possible bursts from SGR1806-20
  39. IPN triangulation of GRB020525
  40. XRF 020427: Sudden Ionospheric Disturbance (SID)
  41. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  42. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  43. IPN triangulation of a burst from SGR1806-20
  44. GRB/XRF 020427, Radio Observations
  45. HST detection of the likely host galaxy of GRB 020124
  46. GRB020405 field photometry at ESO
  47. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  48. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  49. GRB020321 : Optical observations.
  50. GRB020427 BeppoSAX NFI Observation
  51. XRF 020427
  52. GRB020331: Third Epoch and Revised Second Epoch Optical
  53. The end of BSAX GRB activities
  54. GRB 020410, Radio Observations
  55. GRB 020418: Optical observations
  56. GRB 020124: Optical observations
  57. GRB 020418: Optical observations
  58. IPN triangulation of GRB020418
  59. GRB020405: VLT observations of the OT environment
  60. GRB020410: BeppoSAX NFI observations refined analysis
  61. GRB 020409: Optical Observations
  62. Mars Odyssey joins the IPN
  63. IPN triangulation of GRB020413
  64. GRB 020409, 2-nd epoch optical observations at Terskol.
  65. GRB020405: predicted break
  66. GRB 020409: Optical observations
  67. GRB 020409, No Optical Detection to R = 22
  68. GRB020410: second BeppoSAX NFI observation
  69. GRB 020409: No Evidence for an Optical Afterglow
  70. GRB 020409, 2nd epoch optical observations
  71. GRB 020331 Kyoto observation on March 31
  72. GRB 020409
  73. GRB 020409 SARA Observations
  74. GRB "020411"
  75. GRB 020409, No Optical Detection to R = 20
  76. GRB020410: BeppoSAX NFI observation
  77. GRB 020409: Optical observations
  78. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  79. GRB 020410, optical observations
  80. BeppoSAX ALERT: possible GRB020411
  81. GRB 020409, optical observations
  82. GRB 020409: Optical Observations
  83. GRB020406(?), optical observations
  84. GRB020410, optical observations
  85. BeppoSAX ALERT: possible GRB020410
  86. X-ray afterglow of GRB020321
  87. BeppoSAX GRB : GRB020409
  88. GRB020331: Confirmation of Afterglow Candidate with Magellan
  89. GRB020405: VLT optical observations and V band decay slope
  90. GRB020331 optical observations with RIMOTS
  91. GRB020124 optical observations with RIBOTS/RIMOTS
  92. GRB 020321: Candidate X-ray Counterparts
  93. ASM GRB candidate 020406 refined error box
  94. GRB 020405: Moderate-resolution spectroscopy
  95. GRB020331: Optical Observations of Afterglow Candidate
  96. GRB020406(?), optical observations
  97. GRB020405: VLT optical observations
  98. Revised Photometry of the Optical Afterglow of GRB 020405
  99. GRB020405: OT observations
  100. GRB 020331: Candidate Optical Afterglow

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