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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"

20815 results found.

  1. GRB 000326: Optical Observations
  2. GRB000326, Radio observations
  3. GRB 000307 optical observations
  4. Single error box for GRB000315
  5. GRB000315 [IPN Positions]
  6. GRB000313, Radio observations
  7. GRB 000313 - optical transient in the BATSE error box
  8. GRB 000307, BVRI Field Photometry
  9. GRB 000301C: HST/STIS CCD Imaging of the field
  10. IPN error box for GRB000307
  11. GRB000301C, optical R-band observations
  12. GRB 000301C Optical Observations
  13. GRB 000301C: K' Observations
  14. GRB000301C OT candidate optical observations
  15. GRB000301C - Host galaxy not detected in R (?)
  16. Optical observations of GRB000301c
  17. GRB000301C, Radio observations
  18. GRB000301C, Radio observations
  19. GRB 000301c near-IR observations
  20. GRB 000301C, Optical Color
  21. GRB 000301C, UBVRI field photometry
  22. GRB000301C, near-infrared observations (JHK' photometry)
  23. GRB 000301C: OT confirmed
  24. GRB000301c optical observations
  25. GRB000301c, near-infrared observations
  26. GRB000301C
  27. GRB 000301C : Optical Candidate
  28. GRB000301C: RXTE/ASM and IPN localizations
  29. GRB000301A [IPN Position]
  30. GRB000226 [IPN Position]
  31. HST Observations of GRB 990712
  32. GRB 000214 near-IR observations
  33. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  34. GRB000210, Radio Observations
  35. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  36. GRB 000115, BVRI field photometry
  37. GRB000214: BeppoSAX GRBM and WFC Detection
  38. IPN annulus for GRB000214
  39. BATSE GRB trigger criterion changed
  40. Optical observations of GRB000210
  41. GRB000210 X-ray afterglow
  42. GRB000214: X-ray afterglow candidate
  43. GRB000214 refined BeppoSAX-WFC position
  44. GRB 000210: BATSE Observations
  45. Optical observations of the Chandra X-ray source for GRB000210
  46. GRB000210, Radio Observations
  47. GRB000201, Radio Observations
  48. GRB000210: BeppoSAX GRBM and WFC Detection
  49. GRB000201 Optical Observations
  50. BATSE+IPN location of GRB000131
  51. IPN localization of GRB000131
  52. GRB 000126, optical observations
  53. IPN annulus for GRB000115
  54. GRB991216, UBVRIJHK field photometry
  55. GCN resumes full operations
  56. GRB 991216: Detection of the Host and/or Absorber Galaxy
  57. IPN error box for GRB991216
  58. GRB 991216: Updated BATSE parameters
  59. GRB 991217 (SAX J2303.2+0015) Optical observations
  60. Chandra observation of the X-ray afterglow of GRB991216
  61. SAX J2303.2+0015 Optical observations
  62. IR observations of GRB991216
  63. GRB 991217 (SAX J2303.2+0015) Optical observations
  64. Refined IPN localization of GRB991216
  65. GRB 991216 Radio Observations
  66. GRB 991208 Infrared Detection
  67. GRB991216
  68. GRB 991216--Summary of RXTE Observations
  69. GRB 991216 Optical Observations
  70. GRB 991216, optical observations
  71. GRB 991208 SAO-RAS Spectroscopy
  72. SAX J2303.2+0015: an x-ray/GRB?
  73. GRB 991216, Optical Transient
  74. GRB991216 ('Beethoven Burst') B, R, and K Observations
  75. GRB991216, infrared observations
  76. GRB 991208 optical observations
  77. GRB 991216 Optical Observation
  78. GRB 991216: Extremely bright BATSE burst
  79. GRB991208, optical observations
  80. GRB 991208, Optical Observation
  81. GRB991208, optical observations
  82. GRB 991208 Optical Decay
  83. Optical Observations of GRB991105
  84. GRB 991106, optical observations
  85. BeppoSAX NFI Observation of GRB991106
  86. GRB 991106, radio observations
  87. GRB991106: the first BeppoSAX short GRB detection?
  88. IPN localization of GRB991105
  89. GRB 991106 Optical Observations
  90. GRB991106, optical observation at SAO-RAS
  91. GRB 991106, LOTIS Optical Observations
  92. GRB991105: SAX-GRBM/-WFC detection
  93. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  94. GRB 991014, Optical Observations
  95. GRB 991014 - BeppoSAX NFI observations
  96. GRB 991014, radio observations
  97. GRB 991014, Optical Observations
  98. GRB 991014, optical observations
  99. IPN localization of GRB991014 - CORRECTION
  100. IPN localization of GRB991014

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