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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"

21772 results found.

  1. Optical observations of GRB000301c
  2. GRB000301C, Radio observations
  3. GRB000301C, Radio observations
  4. GRB 000301c near-IR observations
  5. GRB 000301C, UBVRI field photometry
  6. GRB000301C, near-infrared observations (JHK' photometry)
  7. GRB 000301C: OT confirmed
  8. GRB000301c optical observations
  9. GRB000301c, near-infrared observations
  10. GRB000301C
  11. GRB 000301C : Optical Candidate
  12. GRB000301C: RXTE/ASM and IPN localizations
  13. GRB000226 [IPN Position]
  14. HST Observations of GRB 990712
  15. GRB 000214 near-IR observations
  16. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  17. GRB000210, Radio Observations
  18. GRB 000115, BVRI field photometry
  19. GRB000214: BeppoSAX GRBM and WFC Detection
  20. Optical observations of GRB000210
  21. GRB000210 X-ray afterglow
  22. GRB000214: X-ray afterglow candidate
  23. GRB000214 refined BeppoSAX-WFC position
  24. GRB 000210: BATSE Observations
  25. Optical observations of the Chandra X-ray source for GRB000210
  26. GRB000210, Radio Observations
  27. GRB000201, Radio Observations
  28. GRB000210: BeppoSAX GRBM and WFC Detection
  29. Optical observations of GRB000131
  30. GRB000201 Optical Observations
  31. GRB 000201: TAROT optical observations
  32. IPN localization of GRB000131
  33. GRB 000126, optical observations
  34. IPN localization of GRB000126
  35. BATSE Observations of GRB000115
  36. GRB991216, UBVRIJHK field photometry
  37. GCN resumes full operations
  38. IPN error boxes for GRB991229
  39. GRB 991216: Detection of the Host and/or Absorber Galaxy
  40. IPN error boxes for GRB991221
  41. IPN error box for GRB991216
  42. GRB 991217 (SAX J2303.2+0015) Optical observations
  43. Chandra observation of the X-ray afterglow of GRB991216
  44. GRB 991216, optical observations
  45. GRB 991216 Optical spectroscopy/imaging
  46. GRB991216 Optical and IR observations
  47. SAX J2303.2+0015 Optical observations
  48. IR observations of GRB991216
  49. GRB 991217 (SAX J2303.2+0015) Optical observations
  50. GRB991216 Optical and infrared observations of Beethoven Burst
  51. GRB 991216 Radio Observations
  52. GRB 991208 Infrared Detection
  53. GRB991216
  54. GRB 991216--Summary of RXTE Observations
  55. GRB 991216 Optical Observations
  56. GRB 991216, optical observations
  57. GRB 991208 SAO-RAS Spectroscopy
  58. SAX J2303.2+0015: an x-ray/GRB?
  59. GRB 991216, Optical Transient
  60. GRB991216 ('Beethoven Burst') B, R, and K Observations
  61. GRB991216, infrared observations
  62. GRB 991208 optical observations
  63. Lowell/Perkins observation of GRB 991216
  64. GRB 991216 Optical Observation
  65. GRB 991216: Extremely bright BATSE burst
  66. R-band Observations of GRB991208 at TNG
  67. GRB991208, optical observations
  68. GRB 991208, Optical Observation
  69. GRB991208, optical observations
  70. GRB 991208 Optical Decay
  71. Optical Observations of GRB991105
  72. GRB991106: BeppoSAX/BATSE results
  73. GRB 991106, optical observations
  74. BeppoSAX NFI Observation of GRB991106
  75. GRB 991106, radio observations
  76. GRB991106: the first BeppoSAX short GRB detection?
  77. GRB 991106 Optical Observations
  78. GRB991106, optical observation at SAO-RAS
  79. GRB 991106, LOTIS Optical Observations
  80. GRB991105: SAX-GRBM/-WFC detection
  81. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  82. GRB ALERT: GRB991105
  83. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  84. GRB 991014, Optical Observations
  85. GRB 991014 - BeppoSAX NFI observations
  86. GRB 991014, radio observations
  87. GRB 991014, Optical Observations
  88. GRB 991014, optical observations
  89. Super-LOTIS optical observation of GRB991014
  90. Optical Observations of GRB990907
  91. GRB990907 and 990908
  92. GRB990806 BeppoSAX follow up
  93. GRB 990806 Optical observations
  94. Optical Observations of GRB990806
  95. GRB 990806, Optical Observations
  96. GRB 990806, optical observations
  97. GRB 990806, Optical Observations
  98. GRB 990712 Optical Observations
  99. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  100. GRB 990712

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