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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. GRB000301c optical observations
  2. GRB 000301A, Radio Observations
  3. GRB000301C, optical observations
  4. GRB000301c, near-infrared observations
  5. GRB000301C
  6. GRB 000301C : Optical Candidate
  7. Radio observations of the error box of GRB000301A
  8. GRB000301C: RXTE/ASM and IPN localizations
  9. GRB000301A [IPN Position]
  10. GRB000226 [IPN Position]
  11. HST Observations of GRB 990712
  12. GRB 000214 near-IR observations
  13. GRB 000115 Optical observations
  14. GRB 000214, Radio Observations
  15. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  16. GRB000210, Radio Observations
  17. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  18. GRB 000115, BVRI field photometry
  19. GRB000214: BeppoSAX GRBM and WFC Detection
  20. IPN annulus for GRB000214
  21. BATSE GRB trigger criterion changed
  22. Optical observations of GRB000210
  23. GRB000210 X-ray afterglow
  24. GRB000214: X-ray afterglow candidate
  25. GRB000214 refined BeppoSAX-WFC position
  26. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  27. GRB 000210: BATSE Observations
  28. Correction to Chandra Position of GRB000210 afterglow
  29. Optical observations of the Chandra X-ray source for GRB000210
  30. GRB000210, Radio Observations
  31. Optical candidate for GRB000210
  32. Chandra Observations of GRB000210 X-ray Afterglow
  33. IPN triangulation of GRB000210
  34. GRB000210: possible afterglow detection with BeppoSAX NFI
  35. GRB000201, Radio Observations
  36. GRB000210: BeppoSAX GRBM and WFC Detection
  37. SAX_WFC_GRB_NOTICE
  38. SAX_WFC_GRB_NOTICE
  39. Optical observations of GRB000131
  40. GRB000201 Optical Observations
  41. GRB 000201: TAROT optical observations
  42. GRB 000131 Optical Observations
  43. GRB000126 Optical Observations
  44. BATSE GRB trigger criteria changed
  45. GRB 991208, radio observations
  46. BATSE+IPN location of GRB000131
  47. IPN localization of GRB000131
  48. GRB 000126, optical observations
  49. GRB000126, optical observations
  50. BATSE location of GRB000126
  51. IPN localization of GRB000126
  52. GRB 000115 Optical observations
  53. BATSE Observations of GRB000115
  54. Correction to GCN 520 (IPN annulus for GRB000115)
  55. IPN annulus for GRB000115
  56. Second RXTE Observation of GRB 000115
  57. GRB991216, UBVRIJHK field photometry
  58. GRB991216 late optical observation
  59. Single IPN error box for GRB991229
  60. GCN resumes full operations
  61. GRB 991216 VLBA Observations
  62. BEPPOSAX GRBM Localization of GRB991226
  63. IPN error boxes for GRB991229
  64. GRB 991216: J band spectrophotometry
  65. GRB 991216: Detection of the Host and/or Absorber Galaxy
  66. IPN localization of GRB991226
  67. Single IPN error box for GRB991221
  68. IPN error boxes for GRB991221
  69. GRB 991216 RXTE ASM Observations
  70. IPN error box for GRB991216
  71. GRB 991216: Updated BATSE parameters
  72. Lowell/Perkins observation of GRB 991216
  73. GRB 991217 (SAX J2303.2+0015) Optical observations
  74. GRB991217/SAX J2303.2+0015, optical observations
  75. Chandra observation of the X-ray afterglow of GRB991216
  76. GRB 991216, optical observations
  77. GRB 991216 Optical Observations
  78. GRB 991216 Optical spectroscopy/imaging
  79. VLT spectra of GRB991216
  80. GRB991216 Optical and IR observations
  81. K observations of GRB991216
  82. SAX J2303.2+0015 Optical observations
  83. IR observations of GRB991216
  84. GRB991216 radio observations
  85. GRB 991217 (SAX J2303.2+0015) Optical observations
  86. GRB991216 radio observations
  87. GRB991216 Spectroscopy
  88. Lowell/Perkins observation of GRB 991216
  89. GRB991216, optical observations
  90. GRB991216 Optical and infrared observations of Beethoven Burst
  91. Refined IPN localization of GRB991216
  92. GRB 991216 Radio Observations
  93. GRB 991217
  94. GRB 991208 Keck Spectroscopy
  95. GRB 991208 Infrared Detection
  96. GRB991216
  97. GRB 991216--Summary of RXTE Observations
  98. GRB 991216 Optical Observations
  99. GRB 991216, optical observations
  100. GRB 991208 SAO-RAS Spectroscopy

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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