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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"

28055 results found.

  1. GRB010518: a faint BeppoSAX detection
  2. GRB000418: HST/STIS Second-epoch Observations
  3. X-ray precursors to the large flare from SGR 1900+14
  4. GRB010427, Gamma Ray Observations
  5. SGR 1900+14: No evidence of extended X-ray emission
  6. SGR 1900+14 : RXTE observations
  7. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  8. SGR 1900+14: Correction to GCN 1049
  9. GRB 010222 /corrections to VBT data
  10. Millimeter observation of SGR 1900+14
  11. SGR 1900+14: Detection of extended X-ray emission
  12. SGR 1900+14, Chandra observations
  13. SGR1900+14, I-band observations
  14. GRB010412, field photometry
  15. Giant flare from SGR1900+14
  16. GRB 010326b Optical Observations
  17. GRB010412: BeppoSAX GRBM and WFC observations
  18. GRB010324, revised field photometry
  19. REVISED LOCATION OF GRB010326A
  20. GRB 980326: Late-time HST/STIS observations
  21. GRB010324, field photometry
  22. GRB010326B, field photometry
  23. GRB010326, field photometry
  24. GRB010220, field photometry
  25. Further Optical Observations of GRB 010324
  26. GRB010222, CXO X-ray observations
  27. GRB010324, optical observations
  28. GRB010326B: Localization by HETE (2nd GRB for this date)
  29. GRB 010326 optical observations
  30. GRB010326: Refined Localization by HETE
  31. GRB010326: Localization by HETE
  32. Optical Observations of GRB 010324
  33. GRB010222, late-time optical observation
  34. Support extension to the BeppoSAX mission
  35. GRB 010222 - HEGRA GeV/TeV Observations
  36. GRB010222: Chandra X-ray Observatory Observation
  37. GRB010222: Sub-millimeter vanishing act
  38. GRB010222 - Optical observation
  39. GRB 010222, Optical Observations
  40. GRB010222 - Optical observation
  41. GRB 010222: High-Resolution Keck Spectroscopy
  42. GRB 010214, I-band data
  43. GRB 010222
  44. GRB010222 further R-band photometry
  45. GRB010222: R-band data
  46. GRB 010222: Keck Spectroscopy
  47. GRB010214, field photometry
  48. GRB010222, field photometry
  49. GRB010222 further R-band photometry
  50. GRB010222, possible increase of optical decay slope
  51. GRB 010222 Kyoto optical observation
  52. GRB010222 R-BAND OBSERVATION
  53. GRB010214 follow-up from Hanle
  54. GRB 010222: Near-IR Observations
  55. GRB 010222: Optical Observations
  56. GRB010222: Optical decay slope
  57. GRB 010214, Optical Observations
  58. GRB010222, radio observations
  59. GRB010222, optical observations
  60. GRB010222: BeppoSAX/NFI Observations
  61. GRB010214B,Gamma Ray Observations
  62. GRB 010220, simultaneous optical observations
  63. GRB010220: BeppoSAX WFC and GRBM preliminary data
  64. GRB010214, candidate optical afterglow
  65. GRB010214, optical observations
  66. GRB010214: BeppoSAX WFC and GRBM preliminary data
  67. GRB 010214: X-Ray afterglow
  68. GRB 010214 optical observation
  69. GRB010213, Radio Observations
  70. J-Band Observation of GRB 010214.
  71. GRB010213, Near-IR observations
  72. Possible InfraRed Transient of GRB 010214.
  73. GRB 010214, optical observations
  74. GRB010213 detected by HETE
  75. IPN Status Report
  76. HETE Status
  77. IPN/RXTE TRIANGULATION OF GRB010126
  78. GRB010126 Optical Observations
  79. IPN TRIANGULATION OF GRB010126
  80. Optical Observations of GRB 001018 at Keck
  81. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  82. Optical observations of GRB 001018 with JCAM
  83. IPN TRIANGULATION OF GRB010115
  84. IPN TRIANGULATION OF GRB010109
  85. IPN TRIANGULATION OF GRB010109
  86. IPN triangulation of GRB010104
  87. IPN triangulation of GRB010103
  88. H band observation of GRB 001212
  89. IPN triangulation of GRB001219
  90. GRB 001212 Optical Observation
  91. GRB 001212 Optical Observation
  92. GRB 001212 possible OA in 2MASS
  93. IPN triangulation of GRB001212
  94. Confirmation of IPN position for GRB001204
  95. IPN triangulation of GRB001204 (short/hard)
  96. GRB001120, optical observations
  97. WSRT 4.8 GHz observations of GRB001109
  98. IPN triangulation of GRB001120
  99. GRB 001109: deep JHK upper limits
  100. GRB 001109 X-ray afterglow with BeppoSAX

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