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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').
  1. GRB010213, Radio Observations
  2. J-Band Observation of GRB 010214.
  3. GRB010214, Radio Observations
  4. GRB010214, optical observations
  5. GRB010213, optical observations
  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. GRB010213 detected by HETE
  13. GRB010214 refined WFC position
  14. BeppoSAX ALERT: GRB010214
  15. IPN Status Report
  16. HETE Status
  17. GRB010126 opt. obs.
  18. IPN/RXTE TRIANGULATION OF GRB010126
  19. GRB010126: CONCAM crude optical limits during GRB
  20. GRB010126, TNG R-band observations
  21. GRB010126 Optical Observations
  22. GRB010126 optical observations
  23. GRB010126: Optical observations
  24. IPN TRIANGULATION OF GRB010126
  25. IPN/RXTE TRIANGULATION OF GRB010126
  26. GRB 010119, optical observations
  27. GRB010119: Optical observations
  28. Optical Observations of GRB 001018 at Keck
  29. GRB010119, Radio observations
  30. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  31. Optical observations of GRB 001018 with JCAM
  32. IPN TRIANGULATION OF GRB010115
  33. IPN TRIANGULATION OF GRB010109
  34. IPN TRIANGULATION OF GRB010109
  35. GRB010103, optical observations
  36. IPN triangulation of GRB010104
  37. IPN triangulation of GRB010103
  38. GRB 001204: Ks observations
  39. H band observation of GRB 001212
  40. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  41. IPN triangulation of GRB001219
  42. GRB 001212 Optical Observation
  43. GRB 001212 Optical Observation
  44. GRB 001212 optical observation
  45. GRB 001212 possible OA in 2MASS
  46. GRB 001212 possible OA
  47. IPN triangulation of GRB001212
  48. GRB001204: Optical observations
  49. Confirmation of IPN position for GRB001204
  50. GRB001204, Radio observations
  51. IPN triangulation of GRB001204 (short/hard)
  52. GRB 001105, further optical observations
  53. GRB001120: Gunn-i observations
  54. GRB001120: Optical observations
  55. GRB001109, optical observations
  56. GRB001120, optical observations
  57. WSRT 4.8 GHz observations of GRB001109
  58. IPN triangulation of GRB001120
  59. Optical/NIR observations of GRB001109
  60. GRB 001109: deep JHK upper limits
  61. GRB 001109 X-ray afterglow with BeppoSAX
  62. CORRECTION to XMM-Newton observation of GRB001025
  63. GRB001109: Optical observations
  64. GRB001109: BeppoSAX/NFI Observations
  65. GRB001109, R-band optical observations
  66. GRB001109, Radio observations
  67. GRB001109: BeppoSAX refined WFC position
  68. BeppoSAX ALERT: GRB001109
  69. GRB001105 BVRI field photometry correction
  70. GRB001105, BVRI field photometry
  71. GRB 001105, R-band observation
  72. IPN TRIANGULATION OF GRB001105
  73. GRB 001025B, Optical obervations
  74. GRB 991208: HST Imaging of the Host Galaxy
  75. GRB000926: R-image of the host galaxy
  76. GRB 001025B, I-band observations
  77. XMM-Newton observation of GRB001025
  78. GRB001025B, Radio observations
  79. GRB 001025 Optical Observations
  80. GRB 001025A, optical observation
  81. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  82. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  83. IPN triangulation of GRB001025
  84. GRB001007: Optical observations
  85. ASM Localization of GRB 001025
  86. GRB001007, Radio observations
  87. IPN TRIANGULATION OF GRB001020
  88. GRB001019, Optical Observations
  89. GRB 001018, Possible Radio Afterglow
  90. GRB001018, Gamma Ray Observations
  91. IPN TRIANGULATION OF GRB001019
  92. CORRECTION TO PEAK FLUX OF GRB001018
  93. IPN TRIANGULATION OF GRB001018
  94. IPN TRIANGULATION OF GRB 001017
  95. GRB 000926: Improved Absorber Redshift
  96. V,R,I band observations of GRB000926
  97. The Likely Optical/Infrared Afterglow of GRB 001011
  98. HETE positions added to GCN
  99. GRB001011 BeppoSAX/WFC refined position
  100. BeppoSAX ALERT: GRB001011

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