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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"

28056 results found.

  1. GRB000301C: Late-time HST/STIS observation
  2. GRB010518: a faint BeppoSAX detection
  3. GRB000418: HST/STIS Second-epoch Observations
  4. X-ray precursors to the large flare from SGR 1900+14
  5. GRB010427, Gamma Ray Observations
  6. SGR 1900+14: No evidence of extended X-ray emission
  7. SGR 1900+14 : RXTE observations
  8. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  9. SGR 1900+14: Correction to GCN 1049
  10. GRB 010222 /corrections to VBT data
  11. Millimeter observation of SGR 1900+14
  12. SGR 1900+14: Detection of extended X-ray emission
  13. SGR 1900+14, Chandra observations
  14. SGR1900+14, I-band observations
  15. GRB010412, field photometry
  16. Giant flare from SGR1900+14
  17. GRB 010326b Optical Observations
  18. GRB010412: BeppoSAX GRBM and WFC observations
  19. GRB010324, revised field photometry
  20. REVISED LOCATION OF GRB010326A
  21. GRB 980326: Late-time HST/STIS observations
  22. GRB010324, field photometry
  23. GRB010326B, field photometry
  24. GRB010326, field photometry
  25. GRB010220, field photometry
  26. Further Optical Observations of GRB 010324
  27. GRB010222, CXO X-ray observations
  28. GRB010324, optical observations
  29. GRB010326B: Localization by HETE (2nd GRB for this date)
  30. GRB 010326 optical observations
  31. GRB010326: Refined Localization by HETE
  32. GRB010326: Localization by HETE
  33. Optical Observations of GRB 010324
  34. GRB010222, late-time optical observation
  35. Support extension to the BeppoSAX mission
  36. GRB 010222 - HEGRA GeV/TeV Observations
  37. GRB010222: Chandra X-ray Observatory Observation
  38. GRB010222: Sub-millimeter vanishing act
  39. GRB010222 - Optical observation
  40. GRB 010222, Optical Observations
  41. GRB010222 - Optical observation
  42. GRB 010222: High-Resolution Keck Spectroscopy
  43. GRB 010214, I-band data
  44. GRB 010222
  45. GRB010222 further R-band photometry
  46. GRB010222: R-band data
  47. GRB 010222: Keck Spectroscopy
  48. GRB010214, field photometry
  49. GRB010222, field photometry
  50. GRB010222 further R-band photometry
  51. GRB010222, possible increase of optical decay slope
  52. GRB 010222 Kyoto optical observation
  53. GRB010222 R-BAND OBSERVATION
  54. GRB010214 follow-up from Hanle
  55. GRB 010222: Near-IR Observations
  56. GRB 010222: Optical Observations
  57. GRB010222: Optical decay slope
  58. GRB 010214, Optical Observations
  59. GRB010222, radio observations
  60. GRB010222, optical observations
  61. GRB010222: BeppoSAX/NFI Observations
  62. GRB010214B,Gamma Ray Observations
  63. GRB 010220, simultaneous optical observations
  64. GRB010220: BeppoSAX WFC and GRBM preliminary data
  65. GRB010214, candidate optical afterglow
  66. GRB010214, optical observations
  67. GRB010214: BeppoSAX WFC and GRBM preliminary data
  68. GRB 010214: X-Ray afterglow
  69. GRB 010214 optical observation
  70. GRB010213, Radio Observations
  71. J-Band Observation of GRB 010214.
  72. GRB010213, Near-IR observations
  73. Possible InfraRed Transient of GRB 010214.
  74. GRB 010214, optical observations
  75. GRB010213 detected by HETE
  76. IPN Status Report
  77. HETE Status
  78. IPN/RXTE TRIANGULATION OF GRB010126
  79. GRB010126 Optical Observations
  80. IPN TRIANGULATION OF GRB010126
  81. Optical Observations of GRB 001018 at Keck
  82. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  83. Optical observations of GRB 001018 with JCAM
  84. IPN TRIANGULATION OF GRB010115
  85. IPN TRIANGULATION OF GRB010109
  86. IPN TRIANGULATION OF GRB010109
  87. IPN triangulation of GRB010104
  88. IPN triangulation of GRB010103
  89. H band observation of GRB 001212
  90. IPN triangulation of GRB001219
  91. GRB 001212 Optical Observation
  92. GRB 001212 Optical Observation
  93. GRB 001212 possible OA in 2MASS
  94. IPN triangulation of GRB001212
  95. Confirmation of IPN position for GRB001204
  96. IPN triangulation of GRB001204 (short/hard)
  97. GRB001120, optical observations
  98. WSRT 4.8 GHz observations of GRB001109
  99. IPN triangulation of GRB001120
  100. GRB 001109: deep JHK upper limits

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