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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"

26500 results found.

  1. GRB 010326: Optical observations
  2. GRB 010326 optical observations
  3. GRB010326: Refined Localization by HETE
  4. GRB010326: Localization by HETE
  5. Duration, ECT, peak flux and fluence of GRB010324
  6. Optical Observations of GRB 010324
  7. GRB990705, VLT-FORS1 observations of the host galaxy
  8. GRB010222, late-time optical observation
  9. Support extension to the BeppoSAX mission
  10. GRB 010222 - HEGRA GeV/TeV Observations
  11. GRB010222: Sub-millimeter vanishing act
  12. GRB010222 - Optical observation
  13. GRB 010222, Optical Observations
  14. GRB 010222: High-Resolution Keck Spectroscopy
  15. GRB 010214, I-band data
  16. GRB 010222
  17. GRB010222 further R-band photometry
  18. GRB 010222: Keck Spectroscopy
  19. GRB010214, field photometry
  20. GRB010222, field photometry
  21. GRB010222 further R-band photometry
  22. GRB010222, possible increase of optical decay slope
  23. GRB 010222 Kyoto optical observation
  24. GRB010222 R-BAND OBSERVATION
  25. GRB010214 follow-up from Hanle
  26. GRB 010222: Near-IR Observations
  27. GRB 010222: Optical Observations
  28. GRB 010222, Decay Slope Confirmed
  29. GRB 010214, Optical Observations
  30. GRB010222, radio observations
  31. GRB010222, optical observations
  32. GRB010214B,Gamma Ray Observations
  33. GRB 010220, simultaneous optical observations
  34. GRB010220: BeppoSAX WFC and GRBM preliminary data
  35. GRB010214, candidate optical afterglow
  36. GRB010214, optical observations
  37. GRB010214: BeppoSAX WFC and GRBM preliminary data
  38. GRB 010214: X-Ray afterglow
  39. GRB 010214 optical observation
  40. GRB010213 Optical Observation
  41. J-Band Observation of GRB 010214.
  42. GRB010213, Near-IR observations
  43. Possible InfraRed Transient of GRB 010214.
  44. GRB010214 Optical Observation
  45. GRB010213 detected by HETE
  46. IPN Status Report
  47. HETE Status
  48. IPN/RXTE TRIANGULATION OF GRB010126
  49. GRB010126: CONCAM crude optical limits during GRB
  50. GRB010126 Optical Observations
  51. GRB010126 optical observations
  52. GRB010126: Optical observations
  53. IPN TRIANGULATION OF GRB010126
  54. IPN/RXTE TRIANGULATION OF GRB010126
  55. GRB 010119, optical observations
  56. GRB010119: Optical observations
  57. Optical Observations of GRB 001018 at Keck
  58. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  59. Optical observations of GRB 001018 with JCAM
  60. IPN TRIANGULATION OF GRB010115
  61. IPN TRIANGULATION OF GRB010109
  62. IPN TRIANGULATION OF GRB010109
  63. IPN triangulation of GRB010104
  64. IPN triangulation of GRB010103
  65. IPN triangulation of GRB001219
  66. GRB 001212 Optical Observation
  67. GRB 001212 Optical Observation
  68. GRB 001212 possible OA in 2MASS
  69. GRB 001212 possible OA
  70. IPN triangulation of GRB001212
  71. GRB001204: Optical observations
  72. Confirmation of IPN position for GRB001204
  73. IPN triangulation of GRB001204 (short/hard)
  74. GRB 001105, further optical observations
  75. GRB001120, optical observations
  76. IPN triangulation of GRB001120
  77. Optical/NIR observations of GRB001109
  78. GRB 001109: deep JHK upper limits
  79. GRB 001109 X-ray afterglow with BeppoSAX
  80. CORRECTION to XMM-Newton observation of GRB001025
  81. GRB001109: Optical observations
  82. GRB001109, Radio observations
  83. GRB001105 BVRI field photometry correction
  84. GRB001105, BVRI field photometry
  85. GRB 001105, R-band observation
  86. IPN TRIANGULATION OF GRB001105
  87. GRB 001025B, Optical obervations
  88. GRB 991208: HST Imaging of the Host Galaxy
  89. GRB000926: R-image of the host galaxy
  90. GRB 001025B, I-band observations
  91. XMM-Newton observation of GRB001025
  92. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  93. IPN triangulation of GRB001025
  94. GRB001007: Optical observations
  95. GRB001007, Radio observations
  96. IPN TRIANGULATION OF GRB001020
  97. GRB001018, Gamma Ray Observations
  98. IPN TRIANGULATION OF GRB001019
  99. CORRECTION TO PEAK FLUX OF GRB001018
  100. IPN TRIANGULATION OF GRB001018

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