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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"

25718 results found.

  1. GRB 000301C Optical Observations
  2. GRB 000301C: K' Observations
  3. GRB000301C OT candidate optical observations
  4. GRB000301C - Host galaxy not detected in R (?)
  5. Optical observations of GRB000301c
  6. GRB000301C, Radio observations
  7. GRB000301C, Radio observations
  8. GRB000301C, near-infrared observations (JHK' imaging)
  9. GRB 000301c near-IR observations
  10. GRB 000301C, UBVRI field photometry
  11. GRB 000301C: OT confirmed
  12. GRB000301c optical observations
  13. GRB000301C, optical observations
  14. GRB000301C
  15. GRB 000301C : Optical Candidate
  16. GRB000301C: RXTE/ASM and IPN localizations
  17. GRB000226 [IPN Position]
  18. HST Observations of GRB 990712
  19. GRB 000214 near-IR observations
  20. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  21. GRB000210, Radio Observations
  22. GRB 000115, BVRI field photometry
  23. GRB000214: BeppoSAX GRBM and WFC Detection
  24. Optical observations of GRB000210
  25. GRB000210 X-ray afterglow
  26. GRB000214: X-ray afterglow candidate
  27. GRB000214 refined BeppoSAX-WFC position
  28. GRB 000210: BATSE Observations
  29. Optical observations of the Chandra X-ray source for GRB000210
  30. GRB000210, Radio Observations
  31. IPN triangulation of GRB000210
  32. GRB000210: possible afterglow detection with BeppoSAX NFI
  33. GRB000201, Radio Observations
  34. GRB000210: BeppoSAX GRBM and WFC Detection
  35. SAX_WFC_GRB_NOTICE
  36. SAX_WFC_GRB_NOTICE
  37. GRB000201 Optical Observations
  38. GRB 000201: TAROT optical observations
  39. GRB 991208, radio observations
  40. BATSE+IPN location of GRB000131
  41. IPN localization of GRB000131
  42. GRB 000126, optical observations
  43. BATSE Observations of GRB000115
  44. Second RXTE Observation of GRB 000115
  45. GRB991216, UBVRIJHK field photometry
  46. GCN resumes full operations
  47. GRB 991216 VLBA Observations
  48. GRB 991216: J band spectrophotometry
  49. GRB 991216: Detection of the Host and/or Absorber Galaxy
  50. IPN localization of GRB991226
  51. GRB 991216 RXTE ASM Observations
  52. GRB 991216: Updated BATSE parameters
  53. GRB 991217 (SAX J2303.2+0015) Optical observations
  54. Chandra observation of the X-ray afterglow of GRB991216
  55. GRB 991216, optical observations
  56. GRB 991216 Optical spectroscopy/imaging
  57. SAX J2303.2+0015 Optical observations
  58. IR observations of GRB991216
  59. GRB 991217 (SAX J2303.2+0015) Optical observations
  60. GRB991216 Optical and infrared observations of Beethoven Burst
  61. GRB 991216 Radio Observations
  62. GRB 991208 Keck Spectroscopy
  63. GRB 991208 Infrared Detection
  64. GRB991216
  65. GRB 991216--Summary of RXTE Observations
  66. GRB 991216 Optical Observations
  67. GRB 991216, optical observations
  68. GRB 991208 SAO-RAS Spectroscopy
  69. SAX J2303.2+0015: an x-ray/GRB?
  70. GRB 991216, Optical Transient
  71. GRB991216 ('Beethoven Burst') B, R, and K Observations
  72. GRB991216, infrared observations
  73. GRB 991208 optical observations
  74. GRB 991216 Optical Observation
  75. GRB 991216: Extremely bright BATSE burst
  76. R-band Observations of GRB991208 at TNG
  77. GRB991208, optical observations
  78. GRB 991208, Optical Observation
  79. GRB991208, optical observations
  80. GRB 991208 optical observations
  81. Optical Observations of GRB991105
  82. GRB991106: BeppoSAX/BATSE results
  83. GRB991106, near-infrared observations
  84. BeppoSAX NFI Observation of GRB991106
  85. GRB 991106, radio observations
  86. GRB991106: the first BeppoSAX short GRB detection?
  87. GRB 991105: BATSE Observations
  88. GRB 991106 Optical Observations
  89. GRB991106, optical observation at SAO-RAS
  90. GRB 991106, LOTIS Optical Observations
  91. GRB991105: SAX-GRBM/-WFC detection
  92. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  93. GRB 991014, Optical Observations
  94. GRB 991014 - BeppoSAX NFI observations
  95. GRB 991014, radio observations
  96. GRB 991014, Optical Observations
  97. GRB 991014, optical observations
  98. GRB 990915 optical observations
  99. Optical Observations of GRB990907
  100. GRB990907: BeppoSAX follow up and X-ray afterglow

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