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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"

35948 results found.

  1. GRB 010214: X-Ray afterglow
  2. GRB 010214, Optical Observations
  3. GRB 010214 optical observation
  4. GRB010213 Optical Observation
  5. J-Band Observation of GRB 010214.
  6. GRB010213, Near-IR observations
  7. Possible InfraRed Transient of GRB 010214.
  8. GRB010214 Optical Observation
  9. GRB010214: BeppoSAX/NFI Observations
  10. GRB010213 (HETE) TAROT observations
  11. GRB 010214, optical observations
  12. BeppoSAX ALERT: GRB010214
  13. IPN Status Report
  14. HETE Status
  15. GRB010126 opt. obs.
  16. IPN/RXTE TRIANGULATION OF GRB010126
  17. GRB010126: CONCAM crude optical limits during GRB
  18. GRB010126, TNG R-band observations
  19. IPN TRIANGULATION OF GRB010126
  20. IPN/RXTE TRIANGULATION OF GRB010126
  21. GRB 010119, optical observations
  22. GRB010119: Optical observations
  23. Optical Observations of GRB 001018 at Keck
  24. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  25. Optical observations of GRB 001018 with JCAM
  26. IPN TRIANGULATION OF GRB010115
  27. IPN TRIANGULATION OF GRB010109
  28. GRB010103, optical observations
  29. IPN triangulation of GRB010104
  30. IPN triangulation of GRB010103
  31. GRB 001204: Ks observations
  32. H band observation of GRB 001212
  33. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  34. IPN triangulation of GRB001219
  35. GRB 001212 Optical Observation
  36. GRB 001212 Optical Observation
  37. GRB 001212 optical observation
  38. GRB 001212 possible OA in 2MASS
  39. GRB 001212 possible OA
  40. IPN triangulation of GRB001212
  41. Confirmation of IPN position for GRB001204
  42. IPN triangulation of GRB001204 (short/hard)
  43. GRB 001105, further optical observations
  44. GRB001120: Gunn-i observations
  45. GRB001120: Optical observations
  46. GRB001109, optical observations
  47. GRB001120, optical observations
  48. IPN triangulation of GRB001120
  49. Optical/NIR observations of GRB001109
  50. GRB 001109: deep JHK upper limits
  51. GRB 001109 X-ray afterglow with BeppoSAX
  52. GRB001109: Optical observations
  53. GRB001109: BeppoSAX/NFI Observations
  54. GRB001109, R-band optical observations
  55. GRB001109, Radio observations
  56. BeppoSAX ALERT: GRB001109
  57. GRB001105 BVRI field photometry correction
  58. GRB001105, BVRI field photometry
  59. GRB 001105, R-band observation
  60. IPN TRIANGULATION OF GRB001105
  61. GRB 001025B, Optical obervations
  62. GRB 991208: HST Imaging of the Host Galaxy
  63. GRB000926: R-image of the host galaxy
  64. GRB 001025B, I-band observations
  65. GRB 001025 Optical Observations
  66. GRB 001025A, optical observation
  67. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  68. IPN triangulation of GRB001025
  69. ASM Localization of GRB 001025
  70. GRB001007, Radio observations
  71. IPN TRIANGULATION OF GRB001020
  72. GRB001019, Optical Observations
  73. GRB 001018, Possible Radio Afterglow
  74. GRB001018, Gamma Ray Observations
  75. IPN TRIANGULATION OF GRB001019
  76. IPN TRIANGULATION OF GRB001018
  77. IPN TRIANGULATION OF GRB 001017
  78. GRB 000926: Improved Absorber Redshift
  79. V,R,I band observations of GRB000926
  80. The Likely Optical/Infrared Afterglow of GRB 001011
  81. HETE positions added to GCN
  82. BeppoSAX ALERT: GRB001011
  83. GRB 001007, BVR-band observations
  84. GRB000926 - Amateur Optical Observations
  85. CONCAM null result on GRB001005
  86. IPN triangulation of GRB001007
  87. GRB 000926 : the host galaxy
  88. IPN triangulation of GRB001005
  89. GRB 000926 Chandra Observation
  90. IPN triangulation of GRB 001004
  91. Public availability of BeppoSAX data of GRB000926
  92. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  93. GRB 000926, Optical Decay
  94. GRB000926 - Optical observations
  95. GRB000926 - Optical observations
  96. GRB 000926: optical observations
  97. GRB 000926, Optical Observations
  98. GRB000926 K'-band Observation
  99. GRB000926 : increasing optical decay slope
  100. GRB000926 optical observations

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