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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"

24765 results found.

  1. GRB 010629 Optical Observations
  2. SGR1900+14: High Fluence Burst Localized by HETE
  3. GRB010629, optical observations
  4. GRB010629: A Burst Localized by HETE
  5. SGR1900+14: Second Burst Localized by HETE
  6. SGR1900+14: A Burst Localized by HETE
  7. SGR1806-20: A Second, Intense Burst Localized by HETE
  8. SGR1806-20: Localization by HETE
  9. HETE Fully-Automated GCN Notices
  10. GRB000301C: Late-time HST/STIS observation
  11. GRB010518: a faint BeppoSAX detection
  12. GRB000418: HST/STIS Second-epoch Observations
  13. X-ray precursors to the large flare from SGR 1900+14
  14. GRB010427, Gamma Ray Observations
  15. SGR 1900+14: No evidence of extended X-ray emission
  16. SGR 1900+14 : RXTE observations
  17. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  18. SGR 1900+14: Correction to GCN 1049
  19. GRB 010222 /corrections to VBT data
  20. Millimeter observation of SGR 1900+14
  21. SGR 1900+14: Detection of extended X-ray emission
  22. SGR 1900+14, Chandra observations
  23. SGR1900+14, I-band observations
  24. GRB010412, field photometry
  25. Giant flare from SGR1900+14
  26. GRB 010326b Optical Observations
  27. GRB010412: BeppoSAX GRBM and WFC observations
  28. GRB010324, revised field photometry
  29. REVISED LOCATION OF GRB010326A
  30. GRB 980326: Late-time HST/STIS observations
  31. GRB010324, field photometry
  32. GRB010326B, field photometry
  33. GRB010326, field photometry
  34. GRB010220, field photometry
  35. Further Optical Observations of GRB 010324
  36. GRB010222, CXO X-ray observations
  37. GRB010324, optical observations
  38. GRB010326B: Localization by HETE (2nd GRB for this date)
  39. GRB 010326 optical observations
  40. GRB010326: Refined Localization by HETE
  41. GRB010326: Localization by HETE
  42. Optical Observations of GRB 010324
  43. GRB010222, late-time optical observation
  44. Support extension to the BeppoSAX mission
  45. GRB 010222 - HEGRA GeV/TeV Observations
  46. GRB010222: Chandra X-ray Observatory Observation
  47. GRB010222: Sub-millimeter vanishing act
  48. GRB010222 - Optical observation
  49. GRB 010222, Optical Observations
  50. GRB010222 - Optical observation
  51. GRB 010222: High-Resolution Keck Spectroscopy
  52. GRB 010214, I-band data
  53. GRB 010222
  54. GRB010222 further R-band photometry
  55. GRB010222: R-band data
  56. GRB 010222: Keck Spectroscopy
  57. GRB010214, field photometry
  58. GRB010222, field photometry
  59. GRB010222 further R-band photometry
  60. GRB010222, possible increase of optical decay slope
  61. GRB 010222 Kyoto optical observation
  62. GRB010222 R-BAND OBSERVATION
  63. GRB010214 follow-up from Hanle
  64. GRB 010222: Near-IR Observations
  65. GRB 010222: Optical Observations
  66. GRB010222: Optical decay slope
  67. GRB 010214, Optical Observations
  68. GRB010222, radio observations
  69. GRB010222, optical observations
  70. GRB010222: BeppoSAX/NFI Observations
  71. GRB010214B,Gamma Ray Observations
  72. GRB 010220, simultaneous optical observations
  73. GRB010220: BeppoSAX WFC and GRBM preliminary data
  74. GRB010214, candidate optical afterglow
  75. GRB010214, optical observations
  76. GRB010214: BeppoSAX WFC and GRBM preliminary data
  77. GRB 010214: X-Ray afterglow
  78. GRB 010214 optical observation
  79. GRB010213, Radio Observations
  80. J-Band Observation of GRB 010214.
  81. GRB010213, Near-IR observations
  82. Possible InfraRed Transient of GRB 010214.
  83. GRB 010214, optical observations
  84. GRB010213 detected by HETE
  85. IPN Status Report
  86. HETE Status
  87. IPN/RXTE TRIANGULATION OF GRB010126
  88. GRB010126 Optical Observations
  89. IPN TRIANGULATION OF GRB010126
  90. Optical Observations of GRB 001018 at Keck
  91. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  92. Optical observations of GRB 001018 with JCAM
  93. IPN TRIANGULATION OF GRB010115
  94. IPN TRIANGULATION OF GRB010109
  95. IPN TRIANGULATION OF GRB010109
  96. IPN triangulation of GRB010104
  97. IPN triangulation of GRB010103
  98. H band observation of GRB 001212
  99. IPN triangulation of GRB001219
  100. GRB 001212 Optical Observation

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