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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').
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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"

20815 results found.

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

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