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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"

27321 results found.

  1. GRB 010222 - HEGRA GeV/TeV Observations
  2. GRB010222: Chandra X-ray Observatory Observation
  3. GRB010222: Sub-millimeter vanishing act
  4. GRB010222 - Optical observation
  5. GRB 010222, Optical Observations
  6. GRB010222 - Optical observation
  7. GRB 010222: High-Resolution Keck Spectroscopy
  8. GRB 010214, I-band data
  9. GRB 010222
  10. GRB010222 further R-band photometry
  11. GRB010222: R-band data
  12. GRB 010222: Keck Spectroscopy
  13. GRB010214, field photometry
  14. GRB010222, field photometry
  15. GRB010222 further R-band photometry
  16. GRB010222, possible increase of optical decay slope
  17. GRB 010222 Kyoto optical observation
  18. GRB010222 R-BAND OBSERVATION
  19. GRB010214 follow-up from Hanle
  20. GRB 010222: Near-IR Observations
  21. GRB 010222: Optical Observations
  22. GRB010222: Optical decay slope
  23. GRB 010214, Optical Observations
  24. GRB010222, radio observations
  25. GRB010222, optical observations
  26. GRB010222: BeppoSAX/NFI Observations
  27. GRB010214B,Gamma Ray Observations
  28. GRB 010220, simultaneous optical observations
  29. GRB010220: BeppoSAX WFC and GRBM preliminary data
  30. GRB010214, candidate optical afterglow
  31. GRB010214, optical observations
  32. GRB010214: BeppoSAX WFC and GRBM preliminary data
  33. GRB 010214: X-Ray afterglow
  34. GRB 010214 optical observation
  35. GRB010213, Radio Observations
  36. J-Band Observation of GRB 010214.
  37. GRB010213, Near-IR observations
  38. Possible InfraRed Transient of GRB 010214.
  39. GRB 010214, optical observations
  40. GRB010213 detected by HETE
  41. IPN Status Report
  42. HETE Status
  43. IPN/RXTE TRIANGULATION OF GRB010126
  44. GRB010126 Optical Observations
  45. IPN TRIANGULATION OF GRB010126
  46. Optical Observations of GRB 001018 at Keck
  47. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  48. Optical observations of GRB 001018 with JCAM
  49. IPN TRIANGULATION OF GRB010115
  50. IPN TRIANGULATION OF GRB010109
  51. IPN TRIANGULATION OF GRB010109
  52. IPN triangulation of GRB010104
  53. IPN triangulation of GRB010103
  54. H band observation of GRB 001212
  55. IPN triangulation of GRB001219
  56. GRB 001212 Optical Observation
  57. GRB 001212 Optical Observation
  58. GRB 001212 possible OA in 2MASS
  59. IPN triangulation of GRB001212
  60. Confirmation of IPN position for GRB001204
  61. IPN triangulation of GRB001204 (short/hard)
  62. GRB001120, optical observations
  63. WSRT 4.8 GHz observations of GRB001109
  64. IPN triangulation of GRB001120
  65. GRB 001109: deep JHK upper limits
  66. GRB 001109 X-ray afterglow with BeppoSAX
  67. CORRECTION to XMM-Newton observation of GRB001025
  68. GRB001109, Radio observations
  69. GRB001105 BVRI field photometry correction
  70. GRB001105, BVRI field photometry
  71. IPN TRIANGULATION OF GRB001105
  72. GRB 001025B, Optical obervations
  73. GRB 991208: HST Imaging of the Host Galaxy
  74. GRB 001025B, I-band observations
  75. XMM-Newton observation of GRB001025
  76. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  77. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  78. GRB001007: Optical observations
  79. ASM Localization of GRB 001025
  80. GRB001007, Radio observations
  81. GRB 001018, Possible Radio Afterglow
  82. GRB001018, Gamma Ray Observations
  83. IPN TRIANGULATION OF GRB001019
  84. IPN TRIANGULATION OF GRB001018
  85. IPN TRIANGULATION OF GRB 001017
  86. V,R,I band observations of GRB000926
  87. HETE positions added to GCN
  88. GRB000926 - Amateur Optical Observations
  89. CONCAM null result on GRB001005
  90. IPN triangulation of GRB001005
  91. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  92. GRB000926 - Optical observations
  93. GRB000926 - Optical observations
  94. GRB 000926, Optical Decay
  95. GRB000911: VLT infrared observation
  96. GRB 000926, Optical Observations
  97. GRB000926 K'-band Observation
  98. J and K band observations of GRB 000926
  99. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  100. CONCAM crude optical limits before and after GRB000926

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