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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"

43623 results found.

  1. GRB 010629 Optical Observations
  2. GRB010629: Optical Observations
  3. SGR1900+14: High Fluence Burst Localized by HETE
  4. GRB010629, optical observations
  5. IPN triangulation of GRB010629
  6. GRB010629: A Burst Localized by HETE
  7. SGR1900+14: Second Burst Localized by HETE
  8. SGR1900+14: A Burst Localized by HETE
  9. Possible burst from SGR1806-20
  10. IPN detection of SGR1900+14
  11. SGR1806-20: A Second, Intense Burst Localized by HETE
  12. GRB 00630: Host Galaxy
  13. SGR1806-20: Localization by HETE
  14. IPN triangulation of GRB010613
  15. IPN triangulation of GRB010612
  16. IPN triangulation of GRB010612
  17. HETE Fully-Automated GCN Notices
  18. GRB000301C: Late-time HST/STIS observation
  19. GRB010518: a faint BeppoSAX detection
  20. GRB000418: HST/STIS Second-epoch Observations
  21. X-ray precursors to the large flare from SGR 1900+14
  22. GRB010214, optical observations
  23. GRB010427, Gamma Ray Observations
  24. SGR 1900+14: No evidence of extended X-ray emission
  25. SGR 1900+14 : RXTE observations
  26. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  27. SGR1900+14
  28. GRB 010222 /corrections to VBT data
  29. SGR 1900+14: Detection of extended X-ray emission
  30. Chandra Observations of SGR 1900+14
  31. SGR 1900+14, Chandra observations
  32. Chandra Observations of SGR 1900+14
  33. Possible precursor to the SGR1900+14 giant burst
  34. SGR1900+14, I-band observations
  35. IPN Triangulation of the Giant Flare from SGR1900+14
  36. GRB010412, field photometry
  37. Giant flare from SGR1900+14
  38. GRB 010326b Optical Observations
  39. GRB010412: Optical observations
  40. GRB010412: BeppoSAX GRBM and WFC observations
  41. IPN Triangulation of GRB010412
  42. GRB010412: refined positions from BeppoSAX
  43. BeppoSAX GRB ALERT: GRB010412
  44. GRB Observation Report
  45. GRB010324, revised field photometry
  46. REVISED LOCATION OF GRB010326A
  47. GRB 980326: Late-time HST/STIS observations
  48. GRB010324, field photometry
  49. GRB010326B, field photometry
  50. GRB010326, field photometry
  51. GRB010220, field photometry
  52. Further Optical Observations of GRB 010324
  53. GRB010222, CXO X-ray observations
  54. GRB 010326A: Further optical observations
  55. GRB010324: BeppoSAX/GRBM data
  56. GRB 010326B: Optical observations
  57. GRB010324, optical observations
  58. GRB010326B: Localization by HETE (2nd GRB for this date)
  59. GRB 010326: Optical observations
  60. GRB 010326 optical observations
  61. GRB010326: Refined Localization by HETE
  62. GRB010326: Localization by HETE
  63. Duration, ECT, peak flux and fluence of GRB010324
  64. Optical Observations of GRB 010324
  65. IPN TRIANGULATION OF GRB010324
  66. GRB990705, VLT-FORS1 observations of the host galaxy
  67. GRB010222, late-time optical observation
  68. Support extension to the BeppoSAX mission
  69. GRB 010222 - HEGRA GeV/TeV Observations
  70. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  71. GRB010222: Chandra X-ray Observatory Observation
  72. GRB010222: Sub-millimeter vanishing act
  73. GRB010222 - Optical observation
  74. GRB 010222, Optical Observations
  75. GRB010220 optical obsercations
  76. GRB010222 - Optical observation
  77. GRB 010222: High-Resolution Keck Spectroscopy
  78. GRB010222: Optical observation and decay
  79. GRB 010214, I-band data
  80. Sub-millimeter Excess/GRB 010222
  81. GRB 010222
  82. GRB 010222 HST/Chandra TOO
  83. GRB010222 further R-band photometry
  84. GRB010222: R-band data
  85. GRB010222 Optical observations
  86. GRB 010222: Keck Spectroscopy
  87. GRB010214, field photometry
  88. GRB010222, field photometry
  89. GRB010222 further R-band photometry
  90. GRB010222, possible increase of optical decay slope
  91. GRB 010222 Kyoto optical observation
  92. GRB010222: fading behavior
  93. GRB 010222 BV optical observations
  94. GRB010222 R-BAND OBSERVATION
  95. GRB 010220: Near-IR Observations
  96. GRB010214 follow-up from Hanle
  97. GRB 010222: Near-IR Observations
  98. GRB 010222: Optical Observations
  99. GRB 010222, Decay Slope Confirmed
  100. GRB010222: Another absorption line system

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