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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"

38354 results found.

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

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