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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"

45452 results found.

  1. IPN triangulation of GRB010612
  2. HETE Fully-Automated GCN Notices
  3. GRB000301C: Late-time HST/STIS observation
  4. GRB010518: a faint BeppoSAX detection
  5. GRB000418: HST/STIS Second-epoch Observations
  6. X-ray precursors to the large flare from SGR 1900+14
  7. GRB010214, optical observations
  8. GRB010427, Gamma Ray Observations
  9. SGR 1900+14: No evidence of extended X-ray emission
  10. SGR 1900+14 : RXTE observations
  11. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  12. SGR1900+14
  13. SGR 1900+14: Correction to GCN 1049
  14. GRB 010222 /corrections to VBT data
  15. Millimeter observation of SGR 1900+14
  16. SGR 1900+14: Detection of extended X-ray emission
  17. Chandra Observations of SGR 1900+14
  18. SGR 1900+14, Chandra observations
  19. Chandra Observations of SGR 1900+14
  20. Possible precursor to the SGR1900+14 giant burst
  21. SGR1900+14, I-band observations
  22. IPN Triangulation of the Giant Flare from SGR1900+14
  23. GRB010412, field photometry
  24. Giant flare from SGR1900+14
  25. GRB 010326b Optical Observations
  26. GRB010412: Optical observations
  27. GRB010412: Optical observations
  28. GRB010412: BeppoSAX GRBM and WFC observations
  29. IPN Triangulation of GRB010412
  30. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  31. BeppoSAX GRB ALERT: GRB010412
  32. GRB Observation Report
  33. GRB010324, revised field photometry
  34. REVISED LOCATION OF GRB010326A
  35. GRB 980326: Late-time HST/STIS observations
  36. GRB010324, field photometry
  37. GRB010326B, field photometry
  38. GRB010326, field photometry
  39. GRB010220, field photometry
  40. Further Optical Observations of GRB 010324
  41. GRB010222, CXO X-ray observations
  42. GRB 010326A: Further optical observations
  43. GRB010324: BeppoSAX/GRBM data
  44. GRB 010326B: Optical observations
  45. GRB010324, optical observations
  46. GRB010326B: Localization by HETE (2nd GRB for this date)
  47. GRB 010326: Optical observations
  48. GRB 010326 optical observations
  49. GRB010326: Refined Localization by HETE
  50. GRB010326: Localization by HETE
  51. Duration, ECT, peak flux and fluence of GRB010324
  52. Optical Observations of GRB 010324
  53. IPN TRIANGULATION OF GRB010324
  54. GRB990705, VLT-FORS1 observations of the host galaxy
  55. GRB010222, late-time optical observation
  56. Support extension to the BeppoSAX mission
  57. GRB 010222 - HEGRA GeV/TeV Observations
  58. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  59. GRB010222: Chandra X-ray Observatory Observation
  60. GRB010222: Sub-millimeter vanishing act
  61. GRB010222 - Optical observation
  62. GRB 010222, Optical Observations
  63. GRB010220 optical obsercations
  64. GRB010222 - Optical observation
  65. GRB 010222: High-Resolution Keck Spectroscopy
  66. GRB010222: Optical observation and decay
  67. GRB 010214, I-band data
  68. Sub-millimeter Excess/GRB 010222
  69. GRB 010222
  70. GRB 010222 HST/Chandra TOO
  71. GRB 010222
  72. GRB010222 further R-band photometry
  73. GRB010222: R-band data
  74. GRB010222 Optical observations
  75. GRB 010222: Keck Spectroscopy
  76. GRB010214, field photometry
  77. GRB010222, field photometry
  78. GRB010222 further R-band photometry
  79. GRB010222, possible increase of optical decay slope
  80. GRB 010222 Kyoto optical observation
  81. GRB010222: fading behavior
  82. GRB 010222 BV optical observations
  83. GRB010220, Optical Observations
  84. GRB010222 R-BAND OBSERVATION
  85. GRB 010220: Near-IR Observations
  86. GRB010214 follow-up from Hanle
  87. GRB 010222: Near-IR Observations
  88. GRB 010222: Optical Observations
  89. GRB 010222, Decay Slope Confirmed
  90. GRB010222: Another absorption line system
  91. GRB010222: Optical decay slope
  92. GRB 010214, Optical Observations
  93. GRB010222: Sub-millimeter detection
  94. GRB010222: R-band fading behavior
  95. GRB010222: Optical Observations
  96. GRB010222, radio observations
  97. GRB010222, optical observations
  98. GRB010222: BeppoSAX/NFI Observations
  99. Redshift of the Optical Transient of GRB010222
  100. GRB010214B,Gamma Ray Observations

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