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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"

42572 results found.

  1. GRB010213 (HETE) TAROT observations
  2. GRB 010214, optical observations
  3. GRB010213 detected by HETE
  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 possible OA in 2MASS
  35. GRB 001212 possible OA
  36. IPN triangulation of GRB001212
  37. GRB001204: Optical observations
  38. GRB001204, Radio observations
  39. IPN triangulation of GRB001204 (short/hard)
  40. GRB 001105, further optical observations
  41. GRB001120: Gunn-i observations
  42. GRB001120: Optical observations
  43. GRB001109, optical observations
  44. GRB001120, optical observations
  45. WSRT 4.8 GHz observations of GRB001109
  46. IPN triangulation of GRB001120
  47. Optical/NIR observations of GRB001109
  48. GRB 001109: deep JHK upper limits
  49. GRB 001109 X-ray afterglow with BeppoSAX
  50. CORRECTION to XMM-Newton observation of GRB001025
  51. GRB001109: Optical observations
  52. GRB001109: BeppoSAX/NFI Observations
  53. GRB001109, R-band optical observations
  54. GRB001109, Radio observations
  55. BeppoSAX ALERT: GRB001109
  56. GRB001105 BVRI field photometry correction
  57. GRB001105, BVRI field photometry
  58. GRB 001105, R-band observation
  59. IPN TRIANGULATION OF GRB001105
  60. GRB 001025B, Optical obervations
  61. GRB 991208: HST Imaging of the Host Galaxy
  62. GRB000926: R-image of the host galaxy
  63. GRB 001025B, I-band observations
  64. XMM-Newton observation of GRB001025
  65. GRB001025B, Radio observations
  66. GRB 001025 Optical Observations
  67. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  68. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  69. IPN triangulation of GRB001025
  70. GRB001007: Optical observations
  71. ASM Localization of GRB 001025
  72. GRB001007, Radio observations
  73. IPN TRIANGULATION OF GRB001020
  74. GRB001019, Optical Observations
  75. GRB 001018, Possible Radio Afterglow
  76. GRB001018, Gamma Ray Observations
  77. IPN TRIANGULATION OF GRB001019
  78. IPN TRIANGULATION OF GRB001018
  79. IPN TRIANGULATION OF GRB 001017
  80. GRB 000926: Improved Absorber Redshift
  81. V,R,I band observations of GRB000926
  82. The Likely Optical/Infrared Afterglow of GRB 001011
  83. HETE positions added to GCN
  84. GRB001011 BeppoSAX/WFC refined position
  85. BeppoSAX ALERT: GRB001011
  86. GRB 001007, BVR-band observations
  87. GRB000926 - Amateur Optical Observations
  88. GRB001007: Optical observations
  89. CONCAM null result on GRB001005
  90. IPN triangulation of GRB001007
  91. GRB 000926 : the host galaxy
  92. HETE-2 Launches Successfully
  93. IPN triangulation of GRB001005
  94. HETE-2 48 hour Launch Delay
  95. GRB 000926 Chandra Observation
  96. IPN triangulation of GRB 001004
  97. Public availability of BeppoSAX data of GRB000926
  98. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  99. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  100. GRB000926 - Optical observations

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