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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. GRB020603, BVRcIc field observations
  2. GRB020531, BVRcIc field photometry
  3. GRB020531 Optical observations with TAROT
  4. GRB020531 Optical observations with TAROT
  5. GRB 020418, optical/near-IR observations
  6. GRB 020531, Radio Observations
  7. IPN triangulation of GRB020604
  8. GRB020531 Optical Observations
  9. GRB020531: Observations with the Chandra X-ray Observatory
  10. GRB 020603: Optical Observations
  11. GRB 020603, R-band observation
  12. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  13. GRB020531: Upper Limit for Detection of Two TAROT Sources
  14. GRB 020603: Optical observations
  15. IPN triangulation of GRB020603 (possible short/hard GRB)
  16. GRB 020531 optical observations with TAROT
  17. Refined IPN error box for GRB020531
  18. GRB020531, optical observations
  19. GRB020531: optical observations
  20. GRB020531, optical observation
  21. GRB020531(=H2042): Optical Observations
  22. IPN triangulation of the short, hard GRB020531 (=H2042)
  23. GRB020531(=H2042): Optical Observations
  24. GRB020531: Optical observations
  25. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  26. GRB 020525: Optical Observations
  27. GRB020525, optical observations
  28. IPN detection of possible bursts from SGR1806-20
  29. IPN triangulation of GRB020525
  30. XRF 020427: Sudden Ionospheric Disturbance (SID)
  31. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  32. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  33. IPN triangulation of a burst from SGR1806-20
  34. GRB/XRF 020427, Radio Observations
  35. HST detection of the likely host galaxy of GRB 020124
  36. GRB020405 field photometry at ESO
  37. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  38. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  39. GRB020321 : Optical observations.
  40. GRB020427 BeppoSAX NFI Observation
  41. XRF 020427
  42. GRB020331: Third Epoch and Revised Second Epoch Optical
  43. The end of BSAX GRB activities
  44. GRB 020410, Radio Observations
  45. GRB 020418: Optical observations
  46. GRB 020124: Optical observations
  47. GRB 020418: Optical observations
  48. IPN triangulation of GRB020418
  49. GRB020405: VLT observations of the OT environment
  50. GRB020410: BeppoSAX NFI observations refined analysis
  51. GRB 020409: Optical Observations
  52. Mars Odyssey joins the IPN
  53. IPN triangulation of GRB020413
  54. GRB 020409, 2-nd epoch optical observations at Terskol.
  55. GRB020405: predicted break
  56. GRB 020409: Optical observations
  57. GRB 020409, No Optical Detection to R = 22
  58. GRB020410: second BeppoSAX NFI observation
  59. GRB 020409: No Evidence for an Optical Afterglow
  60. GRB 020409, 2nd epoch optical observations
  61. GRB 020331 Kyoto observation on March 31
  62. GRB 020409
  63. GRB 020409 SARA Observations
  64. GRB "020411"
  65. GRB 020409, No Optical Detection to R = 20
  66. GRB020410: BeppoSAX NFI observation
  67. GRB 020409: Optical observations
  68. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  69. GRB 020410, optical observations
  70. BeppoSAX ALERT: possible GRB020411
  71. GRB 020409, optical observations
  72. GRB 020409: Optical Observations
  73. GRB020406(?), optical observations
  74. GRB020410, optical observations
  75. BeppoSAX ALERT: possible GRB020410
  76. X-ray afterglow of GRB020321
  77. BeppoSAX GRB : GRB020409
  78. GRB020331: Confirmation of Afterglow Candidate with Magellan
  79. GRB020405: VLT optical observations and V band decay slope
  80. GRB020331 optical observations with RIMOTS
  81. GRB020124 optical observations with RIBOTS/RIMOTS
  82. GRB 020321: Candidate X-ray Counterparts
  83. ASM GRB candidate 020406 refined error box
  84. GRB 020405: Moderate-resolution spectroscopy
  85. GRB020331: Optical Observations of Afterglow Candidate
  86. GRB020406(?), optical observations
  87. GRB020405: VLT optical observations
  88. Revised Photometry of the Optical Afterglow of GRB 020405
  89. GRB020405: OT observations
  90. GRB 020331: Candidate Optical Afterglow
  91. GRB 020405: Decay index
  92. Short RXTE/ASM transient 020406; may be a GRB
  93. GRB020405, Radio Observations
  94. GRB020405: VLT spectroscopy
  95. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  96. V band observations of GRB020405
  97. GRB 020405, U-band observations
  98. GRB 020405: Optical afterglow candidate
  99. IPN localization of GRB020405
  100. GRB011212: Optical Observations

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