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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. Optical observations of GRB000301c
  2. GRB000301C, Radio observations
  3. GRB000301C, Radio observations
  4. GRB000301C optical observations
  5. GRB000301C, near-infrared observations (JHK' imaging)
  6. GRB 000301c near-IR observations
  7. GRB 000301C, Optical Color
  8. GRB000301C, Optical Spectroscopy
  9. GRB 000301C, UBVRI field photometry
  10. GRB 000301C, Optical Observation
  11. GRB000301C, optical observations
  12. GRB000301C 250 GHz detection
  13. GRB 000301C R-band observation
  14. GRB 000301C, Optical Observation
  15. GRB000301C, near-infrared observations (JHK' photometry)
  16. GRB 000301C: OT confirmed
  17. GRB000301c optical observations
  18. GRB 000301A, Radio Observations
  19. GRB000301C, optical observations
  20. GRB000301c, near-infrared observations
  21. GRB000301C
  22. GRB 000301C : Optical Candidate
  23. Radio observations of the error box of GRB000301A
  24. GRB000301C: RXTE/ASM and IPN localizations
  25. GRB000301A [IPN Position]
  26. GRB000226 [IPN Position]
  27. HST Observations of GRB 990712
  28. GRB 000214 near-IR observations
  29. GRB 000115 Optical observations
  30. GRB 000214, Radio Observations
  31. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  32. GRB000210, Radio Observations
  33. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  34. GRB 000115, BVRI field photometry
  35. GRB000214: BeppoSAX GRBM and WFC Detection
  36. IPN annulus for GRB000214
  37. BATSE GRB trigger criterion changed
  38. Optical observations of GRB000210
  39. GRB000210 X-ray afterglow
  40. GRB000214: X-ray afterglow candidate
  41. GRB000214 refined BeppoSAX-WFC position
  42. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  43. GRB 000210: BATSE Observations
  44. Correction to Chandra Position of GRB000210 afterglow
  45. Optical observations of the Chandra X-ray source for GRB000210
  46. GRB000210, Radio Observations
  47. Optical candidate for GRB000210
  48. Chandra Observations of GRB000210 X-ray Afterglow
  49. IPN triangulation of GRB000210
  50. GRB000210: possible afterglow detection with BeppoSAX NFI
  51. GRB000201, Radio Observations
  52. GRB000210: BeppoSAX GRBM and WFC Detection
  53. SAX_WFC_GRB_NOTICE
  54. SAX_WFC_GRB_NOTICE
  55. Optical observations of GRB000131
  56. GRB000201 Optical Observations
  57. GRB 000201: TAROT optical observations
  58. GRB 000131 Optical Observations
  59. GRB000126 Optical Observations
  60. BATSE GRB trigger criteria changed
  61. GRB 991208, radio observations
  62. BATSE+IPN location of GRB000131
  63. IPN localization of GRB000131
  64. GRB 000126, optical observations
  65. GRB000126, optical observations
  66. BATSE location of GRB000126
  67. IPN localization of GRB000126
  68. GRB 000115 Optical observations
  69. BATSE Observations of GRB000115
  70. Correction to GCN 520 (IPN annulus for GRB000115)
  71. IPN annulus for GRB000115
  72. Second RXTE Observation of GRB 000115
  73. GRB991216, UBVRIJHK field photometry
  74. GRB991216 late optical observation
  75. Single IPN error box for GRB991229
  76. GCN resumes full operations
  77. GRB 991216 VLBA Observations
  78. BEPPOSAX GRBM Localization of GRB991226
  79. IPN error boxes for GRB991229
  80. GRB 991216: J band spectrophotometry
  81. GRB 991216: Detection of the Host and/or Absorber Galaxy
  82. IPN localization of GRB991226
  83. Single IPN error box for GRB991221
  84. IPN error boxes for GRB991221
  85. GRB 991216 RXTE ASM Observations
  86. IPN error box for GRB991216
  87. GRB 991216: Updated BATSE parameters
  88. Lowell/Perkins observation of GRB 991216
  89. GRB 991217 (SAX J2303.2+0015) Optical observations
  90. GRB991217/SAX J2303.2+0015, optical observations
  91. Chandra observation of the X-ray afterglow of GRB991216
  92. GRB 991216, optical observations
  93. GRB 991216 Optical Observations
  94. GRB 991216 Optical spectroscopy/imaging
  95. VLT spectra of GRB991216
  96. GRB991216 Optical and IR observations
  97. K observations of GRB991216
  98. SAX J2303.2+0015 Optical observations
  99. IR observations of GRB991216
  100. GRB991216 radio observations

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Download all Circulars as a .tar.gz archive:
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