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

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