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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"

41685 results found.

  1. GRB010222 - Optical observation
  2. GRB 010222, Optical Observations
  3. GRB010220 optical obsercations
  4. GRB010222 - Optical observation
  5. GRB 010222: High-Resolution Keck Spectroscopy
  6. GRB010222: Optical observation and decay
  7. GRB 010214, I-band data
  8. Sub-millimeter Excess/GRB 010222
  9. GRB 010222
  10. GRB 010222 HST/Chandra TOO
  11. GRB010222 further R-band photometry
  12. GRB010222: R-band data
  13. GRB010222 Optical observations
  14. GRB 010222: Keck Spectroscopy
  15. GRB010214, field photometry
  16. GRB010222, field photometry
  17. GRB010222 further R-band photometry
  18. GRB010222, possible increase of optical decay slope
  19. GRB010222: fading behavior
  20. GRB 010222 BV optical observations
  21. GRB010220, Optical Observations
  22. GRB010222 R-BAND OBSERVATION
  23. GRB 010220: Near-IR Observations
  24. GRB010214 follow-up from Hanle
  25. GRB 010222: Near-IR Observations
  26. GRB 010222: Optical Observations
  27. GRB 010222, Decay Slope Confirmed
  28. GRB010222: Another absorption line system
  29. GRB010222: Optical decay slope
  30. GRB 010214, Optical Observations
  31. GRB010222: Sub-millimeter detection
  32. GRB010222: R-band fading behavior
  33. GRB010222: Optical Observations
  34. GRB010222, radio observations
  35. GRB010222, optical observations
  36. GRB010222: BeppoSAX/NFI Observations
  37. Redshift of the Optical Transient of GRB010222
  38. GRB010214B,Gamma Ray Observations
  39. GRB010222: possible optical counterpart
  40. GRB010222
  41. GRB010222: BeppoSAX refined position
  42. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  43. GRB010220, Radio and Optical Observations
  44. GRB 010220, simultaneous optical observations
  45. GRB010220: BeppoSAX WFC and GRBM preliminary data
  46. GRB010214, candidate optical afterglow
  47. GRB010214, optical observations
  48. GRB010214: BeppoSAX WFC and GRBM preliminary data
  49. GRB 010214: X-Ray afterglow
  50. GRB 010214, Optical Observations
  51. GRB 010214 optical observation
  52. GRB010213, Radio Observations
  53. GRB010213 Optical Observation
  54. GRB010213, Radio Observations
  55. J-Band Observation of GRB 010214.
  56. GRB010214, Radio Observations
  57. GRB010214, optical observations
  58. GRB010213, optical observations
  59. Possible InfraRed Transient of GRB 010214.
  60. GRB010214 Optical Observation
  61. GRB010214: BeppoSAX/NFI Observations
  62. GRB010213 (HETE) TAROT observations
  63. GRB 010214, optical observations
  64. GRB010213 detected by HETE
  65. IPN Status Report
  66. HETE Status
  67. GRB010126 opt. obs.
  68. IPN/RXTE TRIANGULATION OF GRB010126
  69. GRB010126: CONCAM crude optical limits during GRB
  70. GRB010126, TNG R-band observations
  71. GRB010126 Optical Observations
  72. GRB010126 optical observations
  73. GRB010126: Optical observations
  74. IPN/RXTE TRIANGULATION OF GRB010126
  75. GRB 010119, optical observations
  76. GRB010119: Optical observations
  77. Optical Observations of GRB 001018 at Keck
  78. GRB010119, Radio observations
  79. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  80. Optical observations of GRB 001018 with JCAM
  81. IPN TRIANGULATION OF GRB010109
  82. GRB 001204: Ks observations
  83. H band observation of GRB 001212
  84. GRB 001212 Optical Observation
  85. GRB 001212 Optical Observation
  86. GRB 001212 optical observation
  87. GRB 001212 possible OA in 2MASS
  88. GRB 001212 possible OA
  89. GRB001204: Optical observations
  90. Confirmation of IPN position for GRB001204
  91. GRB001204, Radio observations
  92. IPN triangulation of GRB001204 (short/hard)
  93. GRB 001105, further optical observations
  94. GRB001120: Gunn-i observations
  95. GRB001120: Optical observations
  96. GRB001109, optical observations
  97. GRB001120, optical observations
  98. WSRT 4.8 GHz observations of GRB001109
  99. Optical/NIR observations of GRB001109
  100. GRB 001109: deep JHK upper limits

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