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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"

42786 results found.

  1. SGR1900+14
  2. SGR 1900+14: Correction to GCN 1049
  3. GRB 010222 /corrections to VBT data
  4. Millimeter observation of SGR 1900+14
  5. SGR 1900+14: Detection of extended X-ray emission
  6. SGR 1900+14, Chandra observations
  7. Chandra Observations of SGR 1900+14
  8. Possible precursor to the SGR1900+14 giant burst
  9. SGR1900+14, I-band observations
  10. IPN Triangulation of the Giant Flare from SGR1900+14
  11. GRB010412, field photometry
  12. Giant flare from SGR1900+14
  13. GRB 010326b Optical Observations
  14. GRB010412: Optical observations
  15. GRB010412: Optical observations
  16. GRB010412: BeppoSAX GRBM and WFC observations
  17. IPN Triangulation of GRB010412
  18. BeppoSAX GRB ALERT: GRB010412
  19. GRB010324, revised field photometry
  20. REVISED LOCATION OF GRB010326A
  21. GRB 980326: Late-time HST/STIS observations
  22. GRB010324, field photometry
  23. GRB010326B, field photometry
  24. GRB010326, field photometry
  25. GRB010220, field photometry
  26. Further Optical Observations of GRB 010324
  27. GRB010222, CXO X-ray observations
  28. GRB 010326A: Further optical observations
  29. GRB010324: BeppoSAX/GRBM data
  30. GRB 010326B: Optical observations
  31. GRB010324, optical observations
  32. GRB010326B: Localization by HETE (2nd GRB for this date)
  33. GRB 010326: Optical observations
  34. GRB 010326 optical observations
  35. GRB010326: Refined Localization by HETE
  36. GRB010326: Localization by HETE
  37. Duration, ECT, peak flux and fluence of GRB010324
  38. Optical Observations of GRB 010324
  39. IPN TRIANGULATION OF GRB010324
  40. GRB010222, late-time optical observation
  41. Support extension to the BeppoSAX mission
  42. GRB 010222 - HEGRA GeV/TeV Observations
  43. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  44. GRB010222: Chandra X-ray Observatory Observation
  45. GRB010222: Sub-millimeter vanishing act
  46. GRB010222 - Optical observation
  47. GRB 010222, Optical Observations
  48. GRB010220 optical obsercations
  49. GRB010222 - Optical observation
  50. GRB 010222: High-Resolution Keck Spectroscopy
  51. GRB010222: Optical observation and decay
  52. GRB 010214, I-band data
  53. Sub-millimeter Excess/GRB 010222
  54. GRB 010222
  55. GRB 010222 HST/Chandra TOO
  56. GRB 010222
  57. GRB010222 further R-band photometry
  58. GRB010222: R-band data
  59. GRB010222 Optical observations
  60. GRB 010222: Keck Spectroscopy
  61. GRB010214, field photometry
  62. GRB010222, field photometry
  63. GRB010222 further R-band photometry
  64. GRB010222, possible increase of optical decay slope
  65. GRB 010222 Kyoto optical observation
  66. GRB010222: fading behavior
  67. GRB 010222 BV optical observations
  68. GRB010220, Optical Observations
  69. GRB010222 R-BAND OBSERVATION
  70. GRB 010220: Near-IR Observations
  71. GRB010214 follow-up from Hanle
  72. GRB 010222: Near-IR Observations
  73. GRB 010222: Optical Observations
  74. GRB 010222, Decay Slope Confirmed
  75. GRB010222: Another absorption line system
  76. GRB010222: Optical decay slope
  77. GRB010222: Sub-millimeter detection
  78. GRB010222: R-band fading behavior
  79. GRB010222: Optical Observations
  80. GRB010222, radio observations
  81. GRB010222, optical observations
  82. GRB010222: BeppoSAX/NFI Observations
  83. Redshift of the Optical Transient of GRB010222
  84. GRB010214B,Gamma Ray Observations
  85. GRB010222: possible optical counterpart
  86. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  87. GRB010220, Radio and Optical Observations
  88. GRB 010220, simultaneous optical observations
  89. GRB010220: BeppoSAX WFC and GRBM preliminary data
  90. GRB010214, candidate optical afterglow
  91. GRB010214, optical observations
  92. BeppoSAX ALERT: GRB010220
  93. GRB010214: BeppoSAX WFC and GRBM preliminary data
  94. GRB 010214: X-Ray afterglow
  95. GRB 010214, Optical Observations
  96. GRB 010214 optical observation
  97. GRB010213, Radio Observations
  98. GRB010213 Optical Observation
  99. GRB010213, Radio Observations
  100. J-Band Observation of GRB 010214.

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