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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"

41624 results found.

  1. GRB 010222: Near-IR Observations
  2. GRB 010222: Optical Observations
  3. GRB 010222, Decay Slope Confirmed
  4. GRB010222: Another absorption line system
  5. GRB010222: Optical decay slope
  6. GRB 010214, Optical Observations
  7. GRB010222: Sub-millimeter detection
  8. GRB010222: R-band fading behavior
  9. GRB010222: Optical Observations
  10. GRB010222, radio 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: possible optical counterpart
  16. GRB010222
  17. GRB010220, Radio and Optical Observations
  18. GRB 010220, simultaneous optical observations
  19. GRB010220: BeppoSAX WFC and GRBM preliminary data
  20. GRB010214, candidate optical afterglow
  21. GRB010214, optical observations
  22. GRB010214: BeppoSAX WFC and GRBM preliminary data
  23. GRB 010214: X-Ray afterglow
  24. GRB 010214, Optical Observations
  25. GRB 010214 optical observation
  26. GRB010213, Radio Observations
  27. GRB010213 Optical Observation
  28. GRB010213, Radio Observations
  29. J-Band Observation of GRB 010214.
  30. GRB010214, Radio Observations
  31. GRB010214, optical observations
  32. GRB010213, optical observations
  33. GRB010213, Near-IR observations
  34. Possible InfraRed Transient of GRB 010214.
  35. GRB010214 Optical Observation
  36. GRB010214: BeppoSAX/NFI Observations
  37. GRB010213 (HETE) TAROT observations
  38. GRB 010214, optical observations
  39. GRB010213 detected by HETE
  40. HETE Status
  41. GRB010126 opt. obs.
  42. IPN/RXTE TRIANGULATION OF GRB010126
  43. GRB010126, TNG R-band observations
  44. GRB010126 Optical Observations
  45. GRB010126 optical observations
  46. GRB010126: Optical observations
  47. IPN/RXTE TRIANGULATION OF GRB010126
  48. GRB 010119, optical observations
  49. GRB010119: Optical observations
  50. Optical Observations of GRB 001018 at Keck
  51. GRB010119, Radio observations
  52. Optical observations of GRB 001018 with JCAM
  53. IPN TRIANGULATION OF GRB010109
  54. IPN TRIANGULATION OF GRB010109
  55. GRB010103, optical observations
  56. IPN triangulation of GRB010103
  57. GRB 001204: Ks observations
  58. H band observation of GRB 001212
  59. IPN triangulation of GRB001219
  60. GRB 001212 Optical Observation
  61. GRB 001212 Optical Observation
  62. GRB 001212 optical observation
  63. GRB 001212 possible OA
  64. IPN triangulation of GRB001212
  65. GRB001204: Optical observations
  66. Confirmation of IPN position for GRB001204
  67. GRB001204, Radio observations
  68. IPN triangulation of GRB001204 (short/hard)
  69. GRB 001105, further optical observations
  70. GRB001120: Gunn-i observations
  71. GRB001120: Optical observations
  72. GRB001109, optical observations
  73. GRB001120, optical observations
  74. WSRT 4.8 GHz observations of GRB001109
  75. IPN triangulation of GRB001120
  76. Optical/NIR observations of GRB001109
  77. GRB 001109: deep JHK upper limits
  78. GRB 001109 X-ray afterglow with BeppoSAX
  79. GRB001109: Optical observations
  80. GRB001109: BeppoSAX/NFI Observations
  81. GRB001109, R-band optical observations
  82. GRB001109, Radio observations
  83. GRB001105, BVRI field photometry
  84. GRB 001105, R-band observation
  85. GRB 001025B, Optical obervations
  86. GRB 991208: HST Imaging of the Host Galaxy
  87. GRB000926: R-image of the host galaxy
  88. GRB 001025B, I-band observations
  89. XMM-Newton observation of GRB001025
  90. GRB001025B, Radio observations
  91. GRB 001025 Optical Observations
  92. GRB 001025A, optical observation
  93. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  94. GRB001007: Optical observations
  95. ASM Localization of GRB 001025
  96. GRB001007, Radio observations
  97. GRB001019, Optical Observations
  98. GRB 001018, Possible Radio Afterglow
  99. GRB001018, Gamma Ray Observations
  100. V,R,I band observations of GRB000926

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