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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"

35268 results found.

  1. GRB010214 follow-up from Hanle
  2. GRB 010222: Near-IR Observations
  3. GRB 010222: Optical Observations
  4. GRB 010222, Decay Slope Confirmed
  5. GRB010222: Another absorption line system
  6. GRB010222: Optical decay slope
  7. GRB 010214, Optical Observations
  8. GRB010222: Sub-millimeter detection
  9. GRB010222: R-band fading behavior
  10. GRB010222: Optical Observations
  11. GRB010222, optical observations
  12. GRB010222: BeppoSAX/NFI Observations
  13. Redshift of the Optical Transient of GRB010222
  14. GRB010214B,Gamma Ray Observations
  15. GRB010222
  16. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  17. GRB 010220, simultaneous optical observations
  18. GRB010220: BeppoSAX WFC and GRBM preliminary data
  19. BeppoSAX ALERT: GRB010220
  20. GRB010214: BeppoSAX WFC and GRBM preliminary data
  21. GRB 010214: X-Ray afterglow
  22. GRB 010214, Optical Observations
  23. GRB 010214 optical observation
  24. GRB010213 Optical Observation
  25. J-Band Observation of GRB 010214.
  26. GRB010213, Near-IR observations
  27. Possible InfraRed Transient of GRB 010214.
  28. GRB010214 Optical Observation
  29. GRB010214: BeppoSAX/NFI Observations
  30. GRB010213 (HETE) TAROT observations
  31. GRB 010214, optical observations
  32. BeppoSAX ALERT: GRB010214
  33. IPN Status Report
  34. HETE Status
  35. GRB010126 opt. obs.
  36. IPN/RXTE TRIANGULATION OF GRB010126
  37. GRB010126: CONCAM crude optical limits during GRB
  38. GRB010126, TNG R-band observations
  39. IPN TRIANGULATION OF GRB010126
  40. IPN/RXTE TRIANGULATION OF GRB010126
  41. GRB 010119, optical observations
  42. GRB010119: Optical observations
  43. Optical Observations of GRB 001018 at Keck
  44. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  45. Optical observations of GRB 001018 with JCAM
  46. IPN TRIANGULATION OF GRB010115
  47. IPN TRIANGULATION OF GRB010109
  48. GRB010103, optical observations
  49. IPN triangulation of GRB010104
  50. IPN triangulation of GRB010103
  51. GRB 001204: Ks observations
  52. H band observation of GRB 001212
  53. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  54. IPN triangulation of GRB001219
  55. GRB 001212 Optical Observation
  56. GRB 001212 Optical Observation
  57. GRB 001212 optical observation
  58. GRB 001212 possible OA in 2MASS
  59. GRB 001212 possible OA
  60. IPN triangulation of GRB001212
  61. Confirmation of IPN position for GRB001204
  62. IPN triangulation of GRB001204 (short/hard)
  63. GRB 001105, further optical observations
  64. GRB001120: Gunn-i observations
  65. GRB001120: Optical observations
  66. GRB001109, optical observations
  67. GRB001120, optical observations
  68. IPN triangulation of GRB001120
  69. Optical/NIR observations of GRB001109
  70. GRB 001109: deep JHK upper limits
  71. GRB 001109 X-ray afterglow with BeppoSAX
  72. GRB001109: Optical observations
  73. GRB001109: BeppoSAX/NFI Observations
  74. GRB001109, R-band optical observations
  75. GRB001109, Radio observations
  76. BeppoSAX ALERT: GRB001109
  77. GRB001105 BVRI field photometry correction
  78. GRB001105, BVRI field photometry
  79. GRB 001105, R-band observation
  80. IPN TRIANGULATION OF GRB001105
  81. GRB 001025B, Optical obervations
  82. GRB 991208: HST Imaging of the Host Galaxy
  83. GRB000926: R-image of the host galaxy
  84. GRB 001025B, I-band observations
  85. GRB 001025 Optical Observations
  86. GRB 001025A, optical observation
  87. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  88. IPN triangulation of GRB001025
  89. ASM Localization of GRB 001025
  90. GRB001007, Radio observations
  91. IPN TRIANGULATION OF GRB001020
  92. GRB001019, Optical Observations
  93. GRB 001018, Possible Radio Afterglow
  94. GRB001018, Gamma Ray Observations
  95. IPN TRIANGULATION OF GRB001019
  96. IPN TRIANGULATION OF GRB001018
  97. IPN TRIANGULATION OF GRB 001017
  98. GRB 000926: Improved Absorber Redshift
  99. V,R,I band observations of GRB000926
  100. The Likely Optical/Infrared Afterglow of GRB 001011

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