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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"

2792 results found.

  1. IPN BURST POSITION
  2. IPN triangulation of GRB021125 (INTEGRAL BURST)
  3. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  4. GRB021104: optical observations
  5. GRB021104: possible optical afterglow
  6. IPN triangulation of GRB021027 (single large error box)
  7. IPN triangulation of GRB021020
  8. GRB021016(=H2397): A Long GRB Localized by HETE
  9. IPN triangulation of GRB021016 (small error box)
  10. IPN triangulation of GRB021008 (two small error boxes)
  11. GRB021004: optical observations and predicted break time
  12. GRB021004: BVRc photometry
  13. GRB 021004: optical counterpart
  14. GRB 021004, SPM optical observations
  15. IPN triangulation of GRB020923 (two error boxes)
  16. IPN triangulation of GRB020914 - clarification and additional information
  17. Confirmation of IPN error box for GRB020910
  18. IPN triangulation of GRB020910
  19. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  20. INTEGRAL GRBs added to GCN
  21. IPN error box for GRB020813
  22. GRB020813: Candidate Optical Afterglow
  23. Correction to IPN error box for GRB020706
  24. GRB 020625, optical observations
  25. GRB 020531: optical photometry of Chandra sources
  26. GRB020604, optical observations
  27. GRB020531: Observations with the Chandra X-ray Observatory
  28. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  29. GRB 020124: Optical observations
  30. GRB 020331 Kyoto observation on March 31
  31. GRB020317: optical observations
  32. GRB020321 optical observations
  33. IPN Upper Limits to a GRB Associated With SN2002ap
  34. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  35. GRB020127: Chandra Observations and Prospective Counterparts
  36. GRB 011211, Optical Observations
  37. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  38. GRB011130 (XRF011130) Chandra Observations
  39. GRB011121: fainter still
  40. BEPPOSAX GRB011121
  41. XRF011030: Chandra Observations
  42. Millimeter observation of SGR 1900+14
  43. IPN Triangulation of GRB010412
  44. GRB010214, candidate optical afterglow
  45. GRB010214 Optical Observation
  46. IPN TRIANGULATION OF GRB010109
  47. IPN TRIANGULATION OF GRB010109
  48. XMM-Newton observation of GRB001025
  49. IPN TRIANGULATION OF GRB001020
  50. IPN TRIANGULATION OF GRB001018
  51. GRB000926 - Amateur Optical Observations
  52. GRB 000926 Chandra Observation
  53. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  54. J and K band observations of GRB 000926
  55. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  56. GRB 000926, Optical Observation
  57. GRB 000926: Optical candidate
  58. Optical candidate for GRB000926
  59. GRB000911: Sub-millimeter observations
  60. IPN localization of GRB000812
  61. IPN localization of GRB000811
  62. GRB 000630: Detection of the Optical Afterglow
  63. GRB000630, Revised BVRI Field Photometry
  64. GRB000630, Optical Observations
  65. GRB000630: Optical observations
  66. possible optical counterpart of GRB 000630
  67. IPN triangulation of GRB000630
  68. GRB 000408, optical observations
  69. Radio observations of the error box of GRB000301A
  70. GRB000301A [IPN Position]
  71. GRB000226 [IPN Position]
  72. IPN localization of GRB991226
  73. GRB991216 Optical and infrared observations of Beethoven Burst
  74. GRB991216 ('Beethoven Burst') B, R, and K Observations
  75. IPN localization of GRB991208
  76. IPN localization of GRB991105
  77. IPN localization of GRB991014 - CORRECTION
  78. IPN localization of GRB991014
  79. IPN error box for GRB990915 (=BATSE 7766)
  80. GRB 990704, optical observations
  81. GRB 990506, optical observations from +1 to +3 hours
  82. GRB 990123: BVRI standards in the field
  83. GRB990123 Optical Observations
  84. GRB990123, early optical counterpart detection
  85. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  86. GRB981226, BeppoSAX Christmas GRB
  87. GRB981220 I-band Observations
  88. BATSE on-board GRB trigger change
  89. GRB980326 IPN annulus
  90. GRB980329 IPN annulus
  91. GRB 971024: Refined analysis by USNOFS Observations
  92. GRB 971024: USNO Observations

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