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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"

45646 results found.

  1. J-Band Observation of GRB 010214.
  2. GRB010214, Radio Observations
  3. GRB010214, optical observations
  4. GRB010213, optical observations
  5. GRB010213, Near-IR observations
  6. Possible InfraRed Transient of GRB 010214.
  7. GRB010214 Optical Observation
  8. GRB010214: BeppoSAX/NFI Observations
  9. GRB010213 (HETE) TAROT observations
  10. GRB 010214, optical observations
  11. GRB010213 detected by HETE
  12. GRB010214 refined WFC position
  13. BeppoSAX ALERT: GRB010214
  14. IPN Status Report
  15. HETE Status
  16. GRB010126 opt. obs.
  17. IPN/RXTE TRIANGULATION OF GRB010126
  18. GRB010126: CONCAM crude optical limits during GRB
  19. GRB010126, TNG R-band observations
  20. GRB010126 Optical Observations
  21. GRB010126 optical observations
  22. GRB010126: Optical observations
  23. IPN TRIANGULATION OF GRB010126
  24. IPN/RXTE TRIANGULATION OF GRB010126
  25. GRB 010119, optical observations
  26. GRB010119: Optical observations
  27. Optical Observations of GRB 001018 at Keck
  28. GRB010119, Radio observations
  29. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  30. Optical observations of GRB 001018 with JCAM
  31. IPN TRIANGULATION OF GRB010115
  32. IPN TRIANGULATION OF GRB010109
  33. IPN TRIANGULATION OF GRB010109
  34. GRB010103, optical observations
  35. IPN triangulation of GRB010104
  36. IPN triangulation of GRB010103
  37. GRB 001204: Ks observations
  38. H band observation of GRB 001212
  39. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  40. IPN triangulation of GRB001219
  41. GRB 001212 Optical Observation
  42. GRB 001212 Optical Observation
  43. GRB 001212 optical observation
  44. GRB 001212 possible OA in 2MASS
  45. GRB 001212 possible OA
  46. IPN triangulation of GRB001212
  47. GRB001204: Optical observations
  48. Confirmation of IPN position for GRB001204
  49. GRB001204, Radio observations
  50. IPN triangulation of GRB001204 (short/hard)
  51. GRB 001105, further optical observations
  52. GRB001120: Gunn-i observations
  53. GRB001120: Optical observations
  54. GRB001109, optical observations
  55. GRB001120, optical observations
  56. WSRT 4.8 GHz observations of GRB001109
  57. IPN triangulation of GRB001120
  58. Optical/NIR observations of GRB001109
  59. GRB 001109: deep JHK upper limits
  60. GRB 001109 X-ray afterglow with BeppoSAX
  61. CORRECTION to XMM-Newton observation of GRB001025
  62. GRB001109: Optical observations
  63. GRB001109: BeppoSAX/NFI Observations
  64. GRB001109, R-band optical observations
  65. GRB001109, Radio observations
  66. GRB001109: BeppoSAX refined WFC position
  67. BeppoSAX ALERT: GRB001109
  68. GRB001105 BVRI field photometry correction
  69. GRB001105, BVRI field photometry
  70. GRB 001105, R-band observation
  71. IPN TRIANGULATION OF GRB001105
  72. GRB 001025B, Optical obervations
  73. GRB 991208: HST Imaging of the Host Galaxy
  74. GRB000926: R-image of the host galaxy
  75. GRB 001025B, I-band observations
  76. XMM-Newton observation of GRB001025
  77. GRB001025B, Radio observations
  78. GRB 001025 Optical Observations
  79. GRB 001025A, optical observation
  80. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  81. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  82. IPN triangulation of GRB001025
  83. GRB001007: Optical observations
  84. ASM Localization of GRB 001025
  85. GRB001007, Radio observations
  86. IPN TRIANGULATION OF GRB001020
  87. GRB001019, Optical Observations
  88. GRB 001018, Possible Radio Afterglow
  89. GRB001018, Gamma Ray Observations
  90. IPN TRIANGULATION OF GRB001019
  91. CORRECTION TO PEAK FLUX OF GRB001018
  92. IPN TRIANGULATION OF GRB001018
  93. IPN TRIANGULATION OF GRB 001017
  94. GRB 000926: Improved Absorber Redshift
  95. V,R,I band observations of GRB000926
  96. The Likely Optical/Infrared Afterglow of GRB 001011
  97. HETE positions added to GCN
  98. GRB001011 BeppoSAX/WFC refined position
  99. BeppoSAX ALERT: GRB001011
  100. GRB 001007, BVR-band observations

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