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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"

28048 results found.

  1. SGR 1900+14: Correction to GCN 1049
  2. GRB 010222 /corrections to VBT data
  3. Millimeter observation of SGR 1900+14
  4. SGR 1900+14: Detection of extended X-ray emission
  5. SGR 1900+14, Chandra observations
  6. SGR1900+14, I-band observations
  7. GRB010412, field photometry
  8. Giant flare from SGR1900+14
  9. GRB 010326b Optical Observations
  10. GRB010412: BeppoSAX GRBM and WFC observations
  11. GRB010324, revised field photometry
  12. REVISED LOCATION OF GRB010326A
  13. GRB 980326: Late-time HST/STIS observations
  14. GRB010324, field photometry
  15. GRB010326B, field photometry
  16. GRB010326, field photometry
  17. GRB010220, field photometry
  18. Further Optical Observations of GRB 010324
  19. GRB010222, CXO X-ray observations
  20. GRB010324, optical observations
  21. GRB010326B: Localization by HETE (2nd GRB for this date)
  22. GRB 010326 optical observations
  23. GRB010326: Refined Localization by HETE
  24. GRB010326: Localization by HETE
  25. Optical Observations of GRB 010324
  26. GRB010222, late-time optical observation
  27. Support extension to the BeppoSAX mission
  28. GRB 010222 - HEGRA GeV/TeV Observations
  29. GRB010222: Chandra X-ray Observatory Observation
  30. GRB010222: Sub-millimeter vanishing act
  31. GRB010222 - Optical observation
  32. GRB 010222, Optical Observations
  33. GRB010222 - Optical observation
  34. GRB 010222: High-Resolution Keck Spectroscopy
  35. GRB 010214, I-band data
  36. GRB 010222
  37. GRB010222 further R-band photometry
  38. GRB010222: R-band data
  39. GRB 010222: Keck Spectroscopy
  40. GRB010214, field photometry
  41. GRB010222, field photometry
  42. GRB010222 further R-band photometry
  43. GRB010222, possible increase of optical decay slope
  44. GRB 010222 Kyoto optical observation
  45. GRB010222 R-BAND OBSERVATION
  46. GRB010214 follow-up from Hanle
  47. GRB 010222: Near-IR Observations
  48. GRB 010222: Optical Observations
  49. GRB010222: Optical decay slope
  50. GRB 010214, Optical Observations
  51. GRB010222, radio observations
  52. GRB010222, optical observations
  53. GRB010222: BeppoSAX/NFI Observations
  54. GRB010214B,Gamma Ray Observations
  55. GRB 010220, simultaneous optical observations
  56. GRB010220: BeppoSAX WFC and GRBM preliminary data
  57. GRB010214, candidate optical afterglow
  58. GRB010214, optical observations
  59. GRB010214: BeppoSAX WFC and GRBM preliminary data
  60. GRB 010214: X-Ray afterglow
  61. GRB 010214 optical observation
  62. GRB010213, Radio Observations
  63. J-Band Observation of GRB 010214.
  64. GRB010213, Near-IR observations
  65. Possible InfraRed Transient of GRB 010214.
  66. GRB 010214, optical observations
  67. GRB010213 detected by HETE
  68. IPN Status Report
  69. HETE Status
  70. IPN/RXTE TRIANGULATION OF GRB010126
  71. GRB010126 Optical Observations
  72. IPN TRIANGULATION OF GRB010126
  73. Optical Observations of GRB 001018 at Keck
  74. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  75. Optical observations of GRB 001018 with JCAM
  76. IPN TRIANGULATION OF GRB010115
  77. IPN TRIANGULATION OF GRB010109
  78. IPN TRIANGULATION OF GRB010109
  79. IPN triangulation of GRB010104
  80. IPN triangulation of GRB010103
  81. H band observation of GRB 001212
  82. IPN triangulation of GRB001219
  83. GRB 001212 Optical Observation
  84. GRB 001212 Optical Observation
  85. GRB 001212 possible OA in 2MASS
  86. IPN triangulation of GRB001212
  87. Confirmation of IPN position for GRB001204
  88. IPN triangulation of GRB001204 (short/hard)
  89. GRB001120, optical observations
  90. WSRT 4.8 GHz observations of GRB001109
  91. IPN triangulation of GRB001120
  92. GRB 001109: deep JHK upper limits
  93. GRB 001109 X-ray afterglow with BeppoSAX
  94. CORRECTION to XMM-Newton observation of GRB001025
  95. GRB001109, Radio observations
  96. GRB001105 BVRI field photometry correction
  97. GRB001105, BVRI field photometry
  98. IPN TRIANGULATION OF GRB001105
  99. GRB 001025B, Optical obervations
  100. GRB 991208: HST Imaging of the Host Galaxy

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