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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. GRB020531 Optical Observations
  2. GRB020531: Observations with the Chandra X-ray Observatory
  3. GRB 020603: Optical Observations
  4. GRB 020603, R-band observation
  5. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  6. GRB020531: Upper Limit for Detection of Two TAROT Sources
  7. GRB 020603: Optical observations
  8. IPN triangulation of GRB020603 (possible short/hard GRB)
  9. GRB 020531 optical observations with TAROT
  10. Refined IPN error box for GRB020531
  11. GRB020531, optical observations
  12. GRB020531: optical observations
  13. GRB020531, optical observation
  14. GRB020531(=H2042): Optical Observations
  15. IPN triangulation of the short, hard GRB020531 (=H2042)
  16. GRB020531(=H2042): Optical Observations
  17. GRB020531: Optical observations
  18. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  19. GRB 020525: Optical Observations
  20. GRB020525, optical observations
  21. IPN detection of possible bursts from SGR1806-20
  22. IPN triangulation of GRB020525
  23. XRF 020427: Sudden Ionospheric Disturbance (SID)
  24. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  25. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  26. IPN triangulation of a burst from SGR1806-20
  27. GRB/XRF 020427, Radio Observations
  28. HST detection of the likely host galaxy of GRB 020124
  29. GRB020405 field photometry at ESO
  30. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  31. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  32. GRB020321 : Optical observations.
  33. GRB020427 BeppoSAX NFI Observation
  34. XRF 020427
  35. GRB020331: Third Epoch and Revised Second Epoch Optical
  36. The end of BSAX GRB activities
  37. GRB 020410, Radio Observations
  38. GRB 020418: Optical observations
  39. GRB 020124: Optical observations
  40. GRB 020418: Optical observations
  41. IPN triangulation of GRB020418
  42. GRB020405: VLT observations of the OT environment
  43. GRB020410: BeppoSAX NFI observations refined analysis
  44. GRB 020409: Optical Observations
  45. Mars Odyssey joins the IPN
  46. IPN triangulation of GRB020413
  47. GRB 020409, 2-nd epoch optical observations at Terskol.
  48. GRB020405: predicted break
  49. GRB 020409: Optical observations
  50. GRB 020409, No Optical Detection to R = 22
  51. GRB020410: second BeppoSAX NFI observation
  52. GRB 020409: No Evidence for an Optical Afterglow
  53. GRB 020409, 2nd epoch optical observations
  54. GRB 020331 Kyoto observation on March 31
  55. GRB 020409
  56. GRB 020409 SARA Observations
  57. GRB "020411"
  58. GRB 020409, No Optical Detection to R = 20
  59. GRB020410: BeppoSAX NFI observation
  60. GRB 020409: Optical observations
  61. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  62. GRB 020410, optical observations
  63. BeppoSAX ALERT: possible GRB020411
  64. GRB 020409, optical observations
  65. GRB 020409: Optical Observations
  66. GRB020406(?), optical observations
  67. GRB020410, optical observations
  68. BeppoSAX ALERT: possible GRB020410
  69. X-ray afterglow of GRB020321
  70. BeppoSAX GRB : GRB020409
  71. GRB020331: Confirmation of Afterglow Candidate with Magellan
  72. GRB020405: VLT optical observations and V band decay slope
  73. GRB020331 optical observations with RIMOTS
  74. GRB020124 optical observations with RIBOTS/RIMOTS
  75. GRB 020321: Candidate X-ray Counterparts
  76. ASM GRB candidate 020406 refined error box
  77. GRB 020405: Moderate-resolution spectroscopy
  78. GRB020331: Optical Observations of Afterglow Candidate
  79. GRB020406(?), optical observations
  80. GRB020405: VLT optical observations
  81. Revised Photometry of the Optical Afterglow of GRB 020405
  82. GRB020405: OT observations
  83. GRB 020331: Candidate Optical Afterglow
  84. GRB 020405: Decay index
  85. Short RXTE/ASM transient 020406; may be a GRB
  86. GRB020405, Radio Observations
  87. GRB020405: VLT spectroscopy
  88. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  89. V band observations of GRB020405
  90. GRB 020405, U-band observations
  91. GRB 020405: Optical afterglow candidate
  92. IPN localization of GRB020405
  93. GRB011212: Optical Observations
  94. GRB 020331: NIR Observations
  95. GRB 020331: NIR Observations
  96. GRB020331 NIR observation at KPNO (re-submission)
  97. GRB02033 NIR observation at KPNO
  98. GRB020331 field photometry
  99. GRB 020331 Optical Observations
  100. GRB 020331, NIR observations

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