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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"

44763 results found.

  1. GRB 000214, Radio Observations
  2. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  3. GRB000210, Radio Observations
  4. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  5. GRB 000115, BVRI field photometry
  6. GRB000214: BeppoSAX GRBM and WFC Detection
  7. IPN annulus for GRB000214
  8. BATSE GRB trigger criterion changed
  9. Optical observations of GRB000210
  10. GRB000210 X-ray afterglow
  11. GRB000214: X-ray afterglow candidate
  12. GRB000214 refined BeppoSAX-WFC position
  13. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  14. GRB 000210: BATSE Observations
  15. Correction to Chandra Position of GRB000210 afterglow
  16. Optical observations of the Chandra X-ray source for GRB000210
  17. GRB000210, Radio Observations
  18. Optical candidate for GRB000210
  19. Chandra Observations of GRB000210 X-ray Afterglow
  20. IPN triangulation of GRB000210
  21. GRB000210: possible afterglow detection with BeppoSAX NFI
  22. GRB000201, Radio Observations
  23. GRB000210: BeppoSAX GRBM and WFC Detection
  24. SAX_WFC_GRB_NOTICE
  25. SAX_WFC_GRB_NOTICE
  26. Optical observations of GRB000131
  27. GRB000201 Optical Observations
  28. GRB 000201: TAROT optical observations
  29. GRB 000131 Optical Observations
  30. GRB000126 Optical Observations
  31. BATSE GRB trigger criteria changed
  32. GRB 991208, radio observations
  33. BATSE+IPN location of GRB000131
  34. IPN localization of GRB000131
  35. GRB 000126, optical observations
  36. GRB000126, optical observations
  37. BATSE location of GRB000126
  38. IPN localization of GRB000126
  39. GRB 000115 Optical observations
  40. BATSE Observations of GRB000115
  41. Correction to GCN 520 (IPN annulus for GRB000115)
  42. IPN annulus for GRB000115
  43. Second RXTE Observation of GRB 000115
  44. GRB991216, UBVRIJHK field photometry
  45. GRB991216 late optical observation
  46. Single IPN error box for GRB991229
  47. GCN resumes full operations
  48. GRB 991216 VLBA Observations
  49. BEPPOSAX GRBM Localization of GRB991226
  50. IPN error boxes for GRB991229
  51. GRB 991216: J band spectrophotometry
  52. GRB 991216: Detection of the Host and/or Absorber Galaxy
  53. IPN localization of GRB991226
  54. Single IPN error box for GRB991221
  55. IPN error boxes for GRB991221
  56. GRB 991216 RXTE ASM Observations
  57. IPN error box for GRB991216
  58. GRB 991216: Updated BATSE parameters
  59. Lowell/Perkins observation of GRB 991216
  60. GRB 991217 (SAX J2303.2+0015) Optical observations
  61. GRB991217/SAX J2303.2+0015, optical observations
  62. Chandra observation of the X-ray afterglow of GRB991216
  63. GRB 991216, optical observations
  64. GRB 991216 Optical Observations
  65. GRB 991216 Optical spectroscopy/imaging
  66. VLT spectra of GRB991216
  67. GRB991216 Optical and IR observations
  68. K observations of GRB991216
  69. SAX J2303.2+0015 Optical observations
  70. IR observations of GRB991216
  71. GRB991216 radio observations
  72. GRB 991217 (SAX J2303.2+0015) Optical observations
  73. GRB991216 radio observations
  74. GRB991216 Spectroscopy
  75. Lowell/Perkins observation of GRB 991216
  76. GRB991216, optical observations
  77. GRB991216 Optical and infrared observations of Beethoven Burst
  78. Refined IPN localization of GRB991216
  79. GRB 991216 Radio Observations
  80. GRB 991217
  81. GRB 991208 Keck Spectroscopy
  82. GRB 991208 Infrared Detection
  83. GRB991216
  84. GRB 991216--Summary of RXTE Observations
  85. GRB 991216 Optical Observations
  86. GRB 991216, optical observations
  87. GRB 991208 SAO-RAS Spectroscopy
  88. SAX J2303.2+0015: an x-ray/GRB?
  89. GRB 991216, Optical Transient
  90. GRB 991216, Optical Afterglow
  91. GRB991216 ('Beethoven Burst') B, R, and K Observations
  92. GRB 991216: Comparison with DPOSS images
  93. GRB991216, infrared observations
  94. GRB991216 Optical Observations
  95. GRB 991208 optical observations
  96. Lowell/Perkins observation of GRB 991216
  97. GRB 991216 Optical Observation
  98. GRB 991208 Keck Spectroscopy
  99. GRB 991216: Extremely bright BATSE burst
  100. R-band Observations of GRB991208 at TNG

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