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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"

45423 results found.

  1. GRB 010214, optical observations
  2. GRB010213 detected by HETE
  3. GRB010214 refined WFC position
  4. BeppoSAX ALERT: GRB010214
  5. IPN Status Report
  6. HETE Status
  7. GRB010126 opt. obs.
  8. IPN/RXTE TRIANGULATION OF GRB010126
  9. GRB010126: CONCAM crude optical limits during GRB
  10. GRB010126, TNG R-band observations
  11. GRB010126 Optical Observations
  12. GRB010126 optical observations
  13. GRB010126: Optical observations
  14. IPN TRIANGULATION OF GRB010126
  15. IPN/RXTE TRIANGULATION OF GRB010126
  16. GRB 010119, optical observations
  17. GRB010119: Optical observations
  18. Optical Observations of GRB 001018 at Keck
  19. GRB010119, Radio observations
  20. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  21. Optical observations of GRB 001018 with JCAM
  22. IPN TRIANGULATION OF GRB010115
  23. IPN TRIANGULATION OF GRB010109
  24. IPN TRIANGULATION OF GRB010109
  25. GRB010103, optical observations
  26. IPN triangulation of GRB010104
  27. IPN triangulation of GRB010103
  28. GRB 001204: Ks observations
  29. H band observation of GRB 001212
  30. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  31. IPN triangulation of GRB001219
  32. GRB 001212 Optical Observation
  33. GRB 001212 Optical Observation
  34. GRB 001212 optical observation
  35. GRB 001212 possible OA in 2MASS
  36. GRB 001212 possible OA
  37. IPN triangulation of GRB001212
  38. GRB001204: Optical observations
  39. Confirmation of IPN position for GRB001204
  40. GRB001204, Radio observations
  41. IPN triangulation of GRB001204 (short/hard)
  42. GRB 001105, further optical observations
  43. GRB001120: Gunn-i observations
  44. GRB001120: Optical observations
  45. GRB001109, optical observations
  46. GRB001120, optical observations
  47. WSRT 4.8 GHz observations of GRB001109
  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. CORRECTION to XMM-Newton observation of GRB001025
  53. GRB001109: Optical observations
  54. GRB001109: BeppoSAX/NFI Observations
  55. GRB001109, R-band optical observations
  56. GRB001109, Radio observations
  57. GRB001109: BeppoSAX refined WFC position
  58. BeppoSAX ALERT: GRB001109
  59. GRB001105, BVRI field photometry
  60. GRB 001105, R-band observation
  61. IPN TRIANGULATION OF GRB001105
  62. GRB 001025B, Optical obervations
  63. GRB 991208: HST Imaging of the Host Galaxy
  64. GRB000926: R-image of the host galaxy
  65. GRB 001025B, I-band observations
  66. XMM-Newton observation of GRB001025
  67. GRB001025B, Radio observations
  68. GRB 001025 Optical Observations
  69. GRB 001025A, optical observation
  70. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  71. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  72. IPN triangulation of GRB001025
  73. GRB001007: Optical observations
  74. ASM Localization of GRB 001025
  75. GRB001007, Radio observations
  76. IPN TRIANGULATION OF GRB001020
  77. GRB001019, Optical Observations
  78. GRB 001018, Possible Radio Afterglow
  79. GRB001018, Gamma Ray Observations
  80. IPN TRIANGULATION OF GRB001019
  81. CORRECTION TO PEAK FLUX OF GRB001018
  82. IPN TRIANGULATION OF GRB001018
  83. IPN TRIANGULATION OF GRB 001017
  84. GRB 000926: Improved Absorber Redshift
  85. V,R,I band observations of GRB000926
  86. The Likely Optical/Infrared Afterglow of GRB 001011
  87. HETE positions added to GCN
  88. GRB001011 BeppoSAX/WFC refined position
  89. BeppoSAX ALERT: GRB001011
  90. GRB 001007, BVR-band observations
  91. GRB000926 - Amateur Optical Observations
  92. GRB001007: Optical observations
  93. CONCAM null result on GRB001005
  94. IPN triangulation of GRB001007
  95. GRB 000926 : the host galaxy
  96. HETE-2 Launches Successfully
  97. IPN triangulation of GRB001005
  98. HETE-2 48 hour Launch Delay
  99. GRB 000926 Chandra Observation
  100. IPN triangulation of GRB 001004

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