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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"

35983 results found.

  1. GRB 010222
  2. GRB 010222 HST/Chandra TOO
  3. GRB 010222
  4. GRB010222 further R-band photometry
  5. GRB010222: R-band data
  6. GRB010222 Optical observations
  7. GRB 010222: Keck Spectroscopy
  8. GRB010214, field photometry
  9. GRB010222, field photometry
  10. GRB010222 further R-band photometry
  11. GRB010222, possible increase of optical decay slope
  12. GRB 010222 Kyoto optical observation
  13. GRB010222: fading behavior
  14. GRB 010222 BV optical observations
  15. GRB 010220: Near-IR Observations
  16. GRB010214 follow-up from Hanle
  17. GRB 010222: Near-IR Observations
  18. GRB 010222: Optical Observations
  19. GRB 010222, Decay Slope Confirmed
  20. GRB010222: Another absorption line system
  21. GRB010222: Optical decay slope
  22. GRB 010214, Optical Observations
  23. GRB010222: Sub-millimeter detection
  24. GRB010222: R-band fading behavior
  25. GRB010222: Optical Observations
  26. GRB010222, optical observations
  27. GRB010222: BeppoSAX/NFI Observations
  28. Redshift of the Optical Transient of GRB010222
  29. GRB010214B,Gamma Ray Observations
  30. GRB010222
  31. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  32. GRB 010220, simultaneous optical observations
  33. GRB010220: BeppoSAX WFC and GRBM preliminary data
  34. BeppoSAX ALERT: GRB010220
  35. GRB010214: BeppoSAX WFC and GRBM preliminary data
  36. GRB 010214: X-Ray afterglow
  37. GRB 010214, Optical Observations
  38. GRB 010214 optical observation
  39. GRB010213 Optical Observation
  40. J-Band Observation of GRB 010214.
  41. GRB010213, Near-IR observations
  42. Possible InfraRed Transient of GRB 010214.
  43. GRB010214 Optical Observation
  44. GRB010214: BeppoSAX/NFI Observations
  45. GRB010213 (HETE) TAROT observations
  46. GRB 010214, optical observations
  47. BeppoSAX ALERT: GRB010214
  48. IPN Status Report
  49. HETE Status
  50. GRB010126 opt. obs.
  51. IPN/RXTE TRIANGULATION OF GRB010126
  52. GRB010126: CONCAM crude optical limits during GRB
  53. GRB010126, TNG R-band observations
  54. IPN TRIANGULATION OF GRB010126
  55. IPN/RXTE TRIANGULATION OF GRB010126
  56. GRB 010119, optical observations
  57. GRB010119: Optical observations
  58. Optical Observations of GRB 001018 at Keck
  59. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  60. Optical observations of GRB 001018 with JCAM
  61. IPN TRIANGULATION OF GRB010115
  62. IPN TRIANGULATION OF GRB010109
  63. GRB010103, optical observations
  64. IPN triangulation of GRB010104
  65. IPN triangulation of GRB010103
  66. GRB 001204: Ks observations
  67. H band observation of GRB 001212
  68. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  69. IPN triangulation of GRB001219
  70. GRB 001212 Optical Observation
  71. GRB 001212 Optical Observation
  72. GRB 001212 optical observation
  73. GRB 001212 possible OA in 2MASS
  74. GRB 001212 possible OA
  75. IPN triangulation of GRB001212
  76. Confirmation of IPN position for GRB001204
  77. IPN triangulation of GRB001204 (short/hard)
  78. GRB 001105, further optical observations
  79. GRB001120: Gunn-i observations
  80. GRB001120: Optical observations
  81. GRB001109, optical observations
  82. GRB001120, optical observations
  83. IPN triangulation of GRB001120
  84. Optical/NIR observations of GRB001109
  85. GRB 001109: deep JHK upper limits
  86. GRB 001109 X-ray afterglow with BeppoSAX
  87. GRB001109: Optical observations
  88. GRB001109: BeppoSAX/NFI Observations
  89. GRB001109, R-band optical observations
  90. GRB001109, Radio observations
  91. BeppoSAX ALERT: GRB001109
  92. GRB001105 BVRI field photometry correction
  93. GRB001105, BVRI field photometry
  94. GRB 001105, R-band observation
  95. IPN TRIANGULATION OF GRB001105
  96. GRB 001025B, Optical obervations
  97. GRB 991208: HST Imaging of the Host Galaxy
  98. GRB000926: R-image of the host galaxy
  99. GRB 001025B, I-band observations
  100. GRB 001025 Optical Observations

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