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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"

27323 results found.

  1. GRB 000301C: A Precise Redshift Determination
  2. GRB 000301C, Optical Observation
  3. GRB 000301C: HST/STIS CCD Imaging of the field
  4. IPN error box for GRB000307
  5. GRB000301C, optical R-band observations
  6. GRB 000301C Optical Observations
  7. GRB 000301C: K' Observations
  8. GRB000301C OT candidate optical observations
  9. GRB000301C - Host galaxy not detected in R (?)
  10. Optical observations of GRB000301c
  11. GRB000301C, Radio observations
  12. GRB000301C, Radio observations
  13. GRB000301C, near-infrared observations (JHK' imaging)
  14. GRB 000301c near-IR observations
  15. GRB 000301C, UBVRI field photometry
  16. GRB 000301C: OT confirmed
  17. GRB000301c optical observations
  18. GRB000301C, optical observations
  19. GRB000301C
  20. GRB 000301C : Optical Candidate
  21. GRB000301C: RXTE/ASM and IPN localizations
  22. GRB000226 [IPN Position]
  23. HST Observations of GRB 990712
  24. GRB 000214 near-IR observations
  25. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  26. GRB000210, Radio Observations
  27. GRB 000115, BVRI field photometry
  28. GRB000214: BeppoSAX GRBM and WFC Detection
  29. Optical observations of GRB000210
  30. GRB000210 X-ray afterglow
  31. GRB000214: X-ray afterglow candidate
  32. GRB000214 refined BeppoSAX-WFC position
  33. GRB 000210: BATSE Observations
  34. Optical observations of the Chandra X-ray source for GRB000210
  35. GRB000210, Radio Observations
  36. IPN triangulation of GRB000210
  37. GRB000210: possible afterglow detection with BeppoSAX NFI
  38. GRB000201, Radio Observations
  39. GRB000210: BeppoSAX GRBM and WFC Detection
  40. SAX_WFC_GRB_NOTICE
  41. SAX_WFC_GRB_NOTICE
  42. GRB000201 Optical Observations
  43. GRB 000201: TAROT optical observations
  44. GRB 991208, radio observations
  45. BATSE+IPN location of GRB000131
  46. IPN localization of GRB000131
  47. GRB 000126, optical observations
  48. BATSE Observations of GRB000115
  49. Second RXTE Observation of GRB 000115
  50. GRB991216, UBVRIJHK field photometry
  51. GCN resumes full operations
  52. GRB 991216 VLBA Observations
  53. GRB 991216: J band spectrophotometry
  54. GRB 991216: Detection of the Host and/or Absorber Galaxy
  55. IPN localization of GRB991226
  56. GRB 991216 RXTE ASM Observations
  57. GRB 991216: Updated BATSE parameters
  58. GRB 991217 (SAX J2303.2+0015) Optical observations
  59. Chandra observation of the X-ray afterglow of GRB991216
  60. GRB 991216, optical observations
  61. GRB 991216 Optical spectroscopy/imaging
  62. SAX J2303.2+0015 Optical observations
  63. IR observations of GRB991216
  64. GRB 991217 (SAX J2303.2+0015) Optical observations
  65. GRB991216 Optical and infrared observations of Beethoven Burst
  66. GRB 991216 Radio Observations
  67. GRB 991208 Keck Spectroscopy
  68. GRB 991208 Infrared Detection
  69. GRB991216
  70. GRB 991216--Summary of RXTE Observations
  71. GRB 991216 Optical Observations
  72. GRB 991216, optical observations
  73. GRB 991208 SAO-RAS Spectroscopy
  74. SAX J2303.2+0015: an x-ray/GRB?
  75. GRB 991216, Optical Transient
  76. GRB991216 ('Beethoven Burst') B, R, and K Observations
  77. GRB991216, infrared observations
  78. GRB 991208 optical observations
  79. GRB 991216 Optical Observation
  80. GRB 991216: Extremely bright BATSE burst
  81. R-band Observations of GRB991208 at TNG
  82. GRB991208, optical observations
  83. GRB 991208, Optical Observation
  84. GRB991208, optical observations
  85. GRB 991208 optical observations
  86. Optical Observations of GRB991105
  87. GRB991106: BeppoSAX/BATSE results
  88. GRB991106, near-infrared observations
  89. BeppoSAX NFI Observation of GRB991106
  90. GRB 991106, radio observations
  91. GRB991106: the first BeppoSAX short GRB detection?
  92. GRB 991105: BATSE Observations
  93. GRB 991106 Optical Observations
  94. GRB991106, optical observation at SAO-RAS
  95. GRB 991106, LOTIS Optical Observations
  96. GRB991105: SAX-GRBM/-WFC detection
  97. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  98. GRB 991014, Optical Observations
  99. GRB 991014 - BeppoSAX NFI observations
  100. GRB 991014, radio observations

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