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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"

32494 results found.

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

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