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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"

24606 results found.

  1. GRB000301C, optical observations
  2. GRB000301C
  3. GRB 000301C : Optical Candidate
  4. GRB000301C: RXTE/ASM and IPN localizations
  5. GRB000226 [IPN Position]
  6. HST Observations of GRB 990712
  7. GRB 000214 near-IR observations
  8. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  9. GRB000210, Radio Observations
  10. GRB 000115, BVRI field photometry
  11. GRB000214: BeppoSAX GRBM and WFC Detection
  12. Optical observations of GRB000210
  13. GRB000210 X-ray afterglow
  14. GRB000214: X-ray afterglow candidate
  15. GRB000214 refined BeppoSAX-WFC position
  16. GRB 000210: BATSE Observations
  17. Optical observations of the Chandra X-ray source for GRB000210
  18. GRB000210, Radio Observations
  19. IPN triangulation of GRB000210
  20. GRB000210: possible afterglow detection with BeppoSAX NFI
  21. GRB000201, Radio Observations
  22. GRB000210: BeppoSAX GRBM and WFC Detection
  23. SAX_WFC_GRB_NOTICE
  24. SAX_WFC_GRB_NOTICE
  25. GRB000201 Optical Observations
  26. GRB 000201: TAROT optical observations
  27. GRB 991208, radio observations
  28. BATSE+IPN location of GRB000131
  29. IPN localization of GRB000131
  30. GRB 000126, optical observations
  31. BATSE Observations of GRB000115
  32. Second RXTE Observation of GRB 000115
  33. GRB991216, UBVRIJHK field photometry
  34. GCN resumes full operations
  35. GRB 991216 VLBA Observations
  36. GRB 991216: J band spectrophotometry
  37. GRB 991216: Detection of the Host and/or Absorber Galaxy
  38. IPN localization of GRB991226
  39. GRB 991216 RXTE ASM Observations
  40. GRB 991216: Updated BATSE parameters
  41. GRB 991217 (SAX J2303.2+0015) Optical observations
  42. Chandra observation of the X-ray afterglow of GRB991216
  43. GRB 991216, optical observations
  44. GRB 991216 Optical spectroscopy/imaging
  45. SAX J2303.2+0015 Optical observations
  46. IR observations of GRB991216
  47. GRB 991217 (SAX J2303.2+0015) Optical observations
  48. GRB991216 Optical and infrared observations of Beethoven Burst
  49. GRB 991216 Radio Observations
  50. GRB 991208 Keck Spectroscopy
  51. GRB 991208 Infrared Detection
  52. GRB991216
  53. GRB 991216--Summary of RXTE Observations
  54. GRB 991216 Optical Observations
  55. GRB 991216, optical observations
  56. GRB 991208 SAO-RAS Spectroscopy
  57. SAX J2303.2+0015: an x-ray/GRB?
  58. GRB 991216, Optical Transient
  59. GRB991216 ('Beethoven Burst') B, R, and K Observations
  60. GRB991216, infrared observations
  61. GRB 991208 optical observations
  62. GRB 991216 Optical Observation
  63. GRB 991216: Extremely bright BATSE burst
  64. R-band Observations of GRB991208 at TNG
  65. GRB991208, optical observations
  66. GRB 991208, Optical Observation
  67. GRB991208, optical observations
  68. GRB 991208 optical observations
  69. Optical Observations of GRB991105
  70. GRB991106: BeppoSAX/BATSE results
  71. GRB991106, near-infrared observations
  72. BeppoSAX NFI Observation of GRB991106
  73. GRB 991106, radio observations
  74. GRB991106: the first BeppoSAX short GRB detection?
  75. GRB 991105: BATSE Observations
  76. GRB 991106 Optical Observations
  77. GRB991106, optical observation at SAO-RAS
  78. GRB 991106, LOTIS Optical Observations
  79. GRB991105: SAX-GRBM/-WFC detection
  80. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  81. GRB 991014, Optical Observations
  82. GRB 991014 - BeppoSAX NFI observations
  83. GRB 991014, radio observations
  84. GRB 991014, Optical Observations
  85. GRB 991014, optical observations
  86. GRB 990915 optical observations
  87. Optical Observations of GRB990907
  88. GRB990907: BeppoSAX follow up and X-ray afterglow
  89. GRB990907 and 990908
  90. GRB 990712 Late Optical Decay and Host Galaxy
  91. GRB990806 BeppoSAX follow up
  92. GRB990806: BATSE Observations
  93. GRB 990806 Optical observations
  94. GRB 990806, Optical Observations
  95. GRB 990806, optical observations
  96. GRB 990806, Optical Observations
  97. GRB990806 UBVRIJHK observations
  98. GRB 990712 Optical Observations
  99. GRB 990712
  100. Late-time HST/STIS Observations of GRB 990510

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