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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"

45446 results found.

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

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