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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"

32488 results found.

  1. GRB010222: possible optical counterpart
  2. GRB010222
  3. GRB010222: BeppoSAX refined position
  4. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  5. GRB010220, Radio and Optical Observations
  6. GRB 010220, simultaneous optical observations
  7. GRB010220: BeppoSAX WFC and GRBM preliminary data
  8. GRB010214, candidate optical afterglow
  9. GRB010214, optical observations
  10. GRB010214: BeppoSAX WFC and GRBM preliminary data
  11. GRB 010214: X-Ray afterglow
  12. GRB 010214, Optical Observations
  13. GRB 010214 optical observation
  14. GRB010213, Radio Observations
  15. GRB010213 Optical Observation
  16. GRB010213, Radio Observations
  17. J-Band Observation of GRB 010214.
  18. GRB010214, Radio Observations
  19. GRB010214, optical observations
  20. GRB010213, optical observations
  21. Possible InfraRed Transient of GRB 010214.
  22. GRB010214 Optical Observation
  23. GRB010213 (HETE) TAROT observations
  24. GRB 010214, optical observations
  25. IPN Status Report
  26. HETE Status
  27. GRB010126 opt. obs.
  28. IPN/RXTE TRIANGULATION OF GRB010126
  29. GRB010126: CONCAM crude optical limits during GRB
  30. GRB010126, TNG R-band observations
  31. GRB010126 Optical Observations
  32. GRB010126 optical observations
  33. GRB010126: Optical observations
  34. IPN/RXTE TRIANGULATION OF GRB010126
  35. GRB 010119, optical observations
  36. GRB010119: Optical observations
  37. Optical Observations of GRB 001018 at Keck
  38. GRB010119, Radio observations
  39. Optical observations of GRB 001018 with JCAM
  40. IPN TRIANGULATION OF GRB010109
  41. GRB 001204: Ks observations
  42. H band observation of GRB 001212
  43. GRB 001212 Optical Observation
  44. GRB 001212 Optical Observation
  45. GRB 001212 optical observation
  46. GRB 001212 possible OA in 2MASS
  47. GRB 001212 possible OA
  48. GRB001204: Optical observations
  49. Confirmation of IPN position for GRB001204
  50. GRB001204, Radio observations
  51. GRB 001105, further optical observations
  52. GRB001120: Gunn-i observations
  53. GRB001109, optical observations
  54. WSRT 4.8 GHz observations of GRB001109
  55. Optical/NIR observations of GRB001109
  56. GRB 001109: deep JHK upper limits
  57. GRB 001109 X-ray afterglow with BeppoSAX
  58. CORRECTION to XMM-Newton observation of GRB001025
  59. GRB001109: Optical observations
  60. GRB001109, R-band optical observations
  61. GRB001109, Radio observations
  62. GRB001105 BVRI field photometry correction
  63. GRB001105, BVRI field photometry
  64. GRB 001105, R-band observation
  65. GRB 991208: HST Imaging of the Host Galaxy
  66. GRB000926: R-image of the host galaxy
  67. GRB 001025B, I-band observations
  68. XMM-Newton observation of GRB001025
  69. GRB001025B, Radio observations
  70. GRB 001025 Optical Observations
  71. GRB 001025A, optical observation
  72. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  73. IPN triangulation of GRB001025
  74. GRB001007: Optical observations
  75. GRB001007, Radio observations
  76. GRB 001018, Possible Radio Afterglow
  77. CORRECTION TO PEAK FLUX OF GRB001018
  78. GRB 000926: Improved Absorber Redshift
  79. V,R,I band observations of GRB000926
  80. The Likely Optical/Infrared Afterglow of GRB 001011
  81. HETE positions added to GCN
  82. GRB 001007, BVR-band observations
  83. GRB001007: Optical observations
  84. CONCAM null result on GRB001005
  85. GRB 000926 : the host galaxy
  86. GRB 000926 Chandra Observation
  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 : increasing optical decay slope

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