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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"

22912 results found.

  1. GRB010222, field photometry
  2. GRB010222 further R-band photometry
  3. GRB 010222 Kyoto optical observation
  4. GRB010222 R-BAND OBSERVATION
  5. GRB 010220: Near-IR Observations
  6. GRB010214 follow-up from Hanle
  7. GRB 010222: Near-IR Observations
  8. GRB 010222: Optical Observations
  9. GRB010222, radio observations
  10. GRB010222, optical observations
  11. Redshift of the Optical Transient of GRB010222
  12. GRB010220, Radio and Optical Observations
  13. GRB 010220, simultaneous optical observations
  14. GRB010220: BeppoSAX WFC and GRBM preliminary data
  15. GRB010214, candidate optical afterglow
  16. GRB010214, optical observations
  17. GRB010214: BeppoSAX WFC and GRBM preliminary data
  18. GRB 010214: X-Ray afterglow
  19. GRB 010214 optical observation
  20. J-Band Observation of GRB 010214.
  21. GRB010213, Near-IR observations
  22. Possible InfraRed Transient of GRB 010214.
  23. GRB 010214, optical observations
  24. GRB010213 detected by HETE
  25. GRB010214 refined WFC position
  26. IPN Status Report
  27. HETE Status
  28. IPN/RXTE TRIANGULATION OF GRB010126
  29. GRB010126, TNG R-band observations
  30. IPN TRIANGULATION OF GRB010126
  31. Optical Observations of GRB 001018 at Keck
  32. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  33. Optical observations of GRB 001018 with JCAM
  34. IPN TRIANGULATION OF GRB010115
  35. IPN TRIANGULATION OF GRB010109
  36. IPN TRIANGULATION OF GRB010109
  37. IPN triangulation of GRB010104
  38. IPN triangulation of GRB010103
  39. IPN triangulation of GRB001219
  40. GRB 001212 Optical Observation
  41. GRB 001212 Optical Observation
  42. IPN triangulation of GRB001212
  43. GRB001204: Optical observations
  44. Confirmation of IPN position for GRB001204
  45. IPN triangulation of GRB001204 (short/hard)
  46. GRB 001105, further optical observations
  47. GRB001120, optical observations
  48. WSRT 4.8 GHz observations of GRB001109
  49. IPN triangulation of GRB001120
  50. Optical/NIR observations of GRB001109
  51. GRB 001109: deep JHK upper limits
  52. GRB 001109 X-ray afterglow with BeppoSAX
  53. CORRECTION to XMM-Newton observation of GRB001025
  54. GRB001109, Radio observations
  55. GRB001105 BVRI field photometry correction
  56. GRB001105, BVRI field photometry
  57. IPN TRIANGULATION OF GRB001105
  58. GRB 001025B, Optical obervations
  59. GRB 991208: HST Imaging of the Host Galaxy
  60. GRB 001025B, I-band observations
  61. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  62. IPN triangulation of GRB001025
  63. GRB001007: Optical observations
  64. ASM Localization of GRB 001025
  65. GRB001007, Radio observations
  66. IPN TRIANGULATION OF GRB001020
  67. IPN TRIANGULATION OF GRB001019
  68. IPN TRIANGULATION OF GRB001018
  69. IPN TRIANGULATION OF GRB 001017
  70. V,R,I band observations of GRB000926
  71. HETE positions added to GCN
  72. GRB000926 - Amateur Optical Observations
  73. GRB001007: Optical observations
  74. CONCAM null result on GRB001005
  75. IPN triangulation of GRB001007
  76. IPN triangulation of GRB001005
  77. GRB 000926 Chandra Observation
  78. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  79. GRB000926 - Optical observations
  80. GRB000926 - Optical observations
  81. GRB 000926, Optical Observations
  82. GRB000926 K'-band Observation
  83. J and K band observations of GRB 000926
  84. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  85. CONCAM crude optical limits before and after GRB000926
  86. GRB 000926: Optical candidate
  87. Optical candidate for GRB000926
  88. IPN triangulation of GRB000926
  89. GRB 000911, BVRI field photometry
  90. IPN triangulation of GRB000925
  91. GRB000911, Radio and Optical observations
  92. GRB000911, Radio observations
  93. GRB000911: Optical observations
  94. IPN triangulation of GRB000911
  95. IPN triangulation of GRB000910
  96. GRB 000830: Optical observations
  97. GRB000830: Optical observations
  98. GRB000830, TNG B-band observations
  99. GRB000830, BVRI field photometry
  100. GRB000830: Optical observations

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