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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"

32495 results found.

  1. GRB010222: Sub-millimeter detection
  2. GRB010222: R-band fading behavior
  3. GRB010222: Optical Observations
  4. GRB010222, radio observations
  5. GRB010222, optical observations
  6. GRB010222: BeppoSAX/NFI Observations
  7. Redshift of the Optical Transient of GRB010222
  8. GRB010222: possible optical counterpart
  9. GRB010222
  10. GRB010222: BeppoSAX refined position
  11. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  12. GRB010220, Radio and Optical Observations
  13. GRB 010220, simultaneous optical observations
  14. GRB010220: BeppoSAX WFC and GRBM preliminary data
  15. GRB010214, candidate optical afterglow
  16. GRB010214, optical observations
  17. GRB010214: BeppoSAX WFC and GRBM preliminary data
  18. GRB 010214: X-Ray afterglow
  19. GRB 010214, Optical Observations
  20. GRB 010214 optical observation
  21. GRB010213, Radio Observations
  22. GRB010213 Optical Observation
  23. GRB010213, Radio Observations
  24. J-Band Observation of GRB 010214.
  25. GRB010214, Radio Observations
  26. GRB010214, optical observations
  27. GRB010213, optical observations
  28. Possible InfraRed Transient of GRB 010214.
  29. GRB010214 Optical Observation
  30. GRB010213 (HETE) TAROT observations
  31. GRB 010214, optical observations
  32. IPN Status Report
  33. HETE Status
  34. GRB010126 opt. obs.
  35. IPN/RXTE TRIANGULATION OF GRB010126
  36. GRB010126: CONCAM crude optical limits during GRB
  37. GRB010126, TNG R-band observations
  38. GRB010126 Optical Observations
  39. GRB010126 optical observations
  40. GRB010126: Optical observations
  41. IPN/RXTE TRIANGULATION OF GRB010126
  42. GRB 010119, optical observations
  43. GRB010119: Optical observations
  44. Optical Observations of GRB 001018 at Keck
  45. GRB010119, Radio observations
  46. Optical observations of GRB 001018 with JCAM
  47. IPN TRIANGULATION OF GRB010109
  48. GRB 001204: Ks observations
  49. H band observation of GRB 001212
  50. GRB 001212 Optical Observation
  51. GRB 001212 Optical Observation
  52. GRB 001212 optical observation
  53. GRB 001212 possible OA in 2MASS
  54. GRB 001212 possible OA
  55. GRB001204: Optical observations
  56. Confirmation of IPN position for GRB001204
  57. GRB001204, Radio observations
  58. GRB 001105, further optical observations
  59. GRB001120: Gunn-i observations
  60. GRB001109, optical observations
  61. WSRT 4.8 GHz observations of GRB001109
  62. Optical/NIR observations of GRB001109
  63. GRB 001109: deep JHK upper limits
  64. GRB 001109 X-ray afterglow with BeppoSAX
  65. CORRECTION to XMM-Newton observation of GRB001025
  66. GRB001109: Optical observations
  67. GRB001109, R-band optical observations
  68. GRB001109, Radio observations
  69. GRB001105 BVRI field photometry correction
  70. GRB001105, BVRI field photometry
  71. GRB 001105, R-band observation
  72. GRB 991208: HST Imaging of the Host Galaxy
  73. GRB000926: R-image of the host galaxy
  74. GRB 001025B, I-band observations
  75. XMM-Newton observation of GRB001025
  76. GRB001025B, Radio observations
  77. GRB 001025 Optical Observations
  78. GRB 001025A, optical observation
  79. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  80. IPN triangulation of GRB001025
  81. GRB001007: Optical observations
  82. GRB001007, Radio observations
  83. GRB 001018, Possible Radio Afterglow
  84. CORRECTION TO PEAK FLUX OF GRB001018
  85. GRB 000926: Improved Absorber Redshift
  86. V,R,I band observations of GRB000926
  87. The Likely Optical/Infrared Afterglow of GRB 001011
  88. HETE positions added to GCN
  89. GRB 001007, BVR-band observations
  90. GRB001007: Optical observations
  91. CONCAM null result on GRB001005
  92. GRB 000926 : the host galaxy
  93. GRB 000926 Chandra Observation
  94. Public availability of BeppoSAX data of GRB000926
  95. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  96. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  97. GRB000926 - Optical observations
  98. GRB000926 - Optical observations
  99. GRB 000926, Optical Decay
  100. GRB000911: VLT infrared observation

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