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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"

44409 results found.

  1. IPN/RXTE TRIANGULATION OF GRB010126
  2. GRB 010119, optical observations
  3. GRB010119: Optical observations
  4. Optical Observations of GRB 001018 at Keck
  5. GRB010119, Radio observations
  6. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  7. Optical observations of GRB 001018 with JCAM
  8. IPN TRIANGULATION OF GRB010115
  9. IPN TRIANGULATION OF GRB010109
  10. IPN TRIANGULATION OF GRB010109
  11. GRB010103, optical observations
  12. IPN triangulation of GRB010104
  13. IPN triangulation of GRB010103
  14. GRB 001204: Ks observations
  15. H band observation of GRB 001212
  16. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  17. IPN triangulation of GRB001219
  18. GRB 001212 Optical Observation
  19. GRB 001212 Optical Observation
  20. GRB 001212 optical observation
  21. GRB 001212 possible OA in 2MASS
  22. GRB 001212 possible OA
  23. IPN triangulation of GRB001212
  24. GRB001204: Optical observations
  25. Confirmation of IPN position for GRB001204
  26. GRB001204, Radio observations
  27. IPN triangulation of GRB001204 (short/hard)
  28. GRB 001105, further optical observations
  29. GRB001120: Gunn-i observations
  30. GRB001120: Optical observations
  31. GRB001109, optical observations
  32. GRB001120, optical observations
  33. WSRT 4.8 GHz observations of GRB001109
  34. IPN triangulation of GRB001120
  35. Optical/NIR observations of GRB001109
  36. GRB 001109: deep JHK upper limits
  37. GRB 001109 X-ray afterglow with BeppoSAX
  38. CORRECTION to XMM-Newton observation of GRB001025
  39. GRB001109: Optical observations
  40. GRB001109: BeppoSAX/NFI Observations
  41. GRB001109, R-band optical observations
  42. GRB001109, Radio observations
  43. GRB001109: BeppoSAX refined WFC position
  44. BeppoSAX ALERT: GRB001109
  45. GRB001105, BVRI field photometry
  46. GRB 001105, R-band observation
  47. IPN TRIANGULATION OF GRB001105
  48. GRB 001025B, Optical obervations
  49. GRB 991208: HST Imaging of the Host Galaxy
  50. GRB000926: R-image of the host galaxy
  51. GRB 001025B, I-band observations
  52. XMM-Newton observation of GRB001025
  53. GRB001025B, Radio observations
  54. GRB 001025 Optical Observations
  55. GRB 001025A, optical observation
  56. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  57. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  58. IPN triangulation of GRB001025
  59. GRB001007: Optical observations
  60. ASM Localization of GRB 001025
  61. GRB001007, Radio observations
  62. IPN TRIANGULATION OF GRB001020
  63. GRB001019, Optical Observations
  64. GRB 001018, Possible Radio Afterglow
  65. GRB001018, Gamma Ray Observations
  66. IPN TRIANGULATION OF GRB001019
  67. CORRECTION TO PEAK FLUX OF GRB001018
  68. IPN TRIANGULATION OF GRB001018
  69. IPN TRIANGULATION OF GRB 001017
  70. GRB 000926: Improved Absorber Redshift
  71. V,R,I band observations of GRB000926
  72. The Likely Optical/Infrared Afterglow of GRB 001011
  73. HETE positions added to GCN
  74. GRB001011 BeppoSAX/WFC refined position
  75. BeppoSAX ALERT: GRB001011
  76. GRB 001007, BVR-band observations
  77. GRB000926 - Amateur Optical Observations
  78. GRB001007: Optical observations
  79. CONCAM null result on GRB001005
  80. IPN triangulation of GRB001007
  81. GRB 000926 : the host galaxy
  82. HETE-2 Launches Successfully
  83. IPN triangulation of GRB001005
  84. HETE-2 48 hour Launch Delay
  85. GRB 000926 Chandra Observation
  86. IPN triangulation of GRB 001004
  87. Public availability of BeppoSAX data of GRB000926
  88. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  89. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  90. GRB000926 - Optical observations
  91. GRB000926 - Optical observations
  92. GRB 000926, Optical Decay
  93. GRB000911: VLT infrared observation
  94. GRB000926 - Optical observations
  95. GRB000926 - Optical observations
  96. GRB 000926: optical observations
  97. GRB 000926, Optical Observations
  98. GRB000926 - Optical observations
  99. GRB000911: optical VLT observations
  100. GRB000926 K'-band Observation

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