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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"

45463 results found.

  1. GRB 000301C : Optical Candidate
  2. Radio observations of the error box of GRB000301A
  3. GRB000301C: RXTE/ASM and IPN localizations
  4. GRB000226 [IPN Position]
  5. HST Observations of GRB 990712
  6. GRB 000214 near-IR observations
  7. GRB 000115 Optical observations
  8. GRB 000214, Radio Observations
  9. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  10. GRB000210, Radio Observations
  11. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  12. GRB 000115, BVRI field photometry
  13. GRB000214: BeppoSAX GRBM and WFC Detection
  14. IPN annulus for GRB000214
  15. Optical observations of GRB000210
  16. GRB000210 X-ray afterglow
  17. GRB000214: X-ray afterglow candidate
  18. GRB000214 refined BeppoSAX-WFC position
  19. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  20. GRB 000210: BATSE Observations
  21. Correction to Chandra Position of GRB000210 afterglow
  22. Optical observations of the Chandra X-ray source for GRB000210
  23. GRB000210, Radio Observations
  24. Optical candidate for GRB000210
  25. Chandra Observations of GRB000210 X-ray Afterglow
  26. IPN triangulation of GRB000210
  27. GRB000210: possible afterglow detection with BeppoSAX NFI
  28. GRB000201, Radio Observations
  29. GRB000210: BeppoSAX GRBM and WFC Detection
  30. Optical observations of GRB000131
  31. GRB000201 Optical Observations
  32. GRB 000201: TAROT optical observations
  33. GRB 000131 Optical Observations
  34. GRB000126 Optical Observations
  35. GRB 991208, radio observations
  36. BATSE+IPN location of GRB000131
  37. IPN localization of GRB000131
  38. GRB 000126, optical observations
  39. GRB000126, optical observations
  40. BATSE location of GRB000126
  41. IPN localization of GRB000126
  42. GRB 000115 Optical observations
  43. BATSE Observations of GRB000115
  44. Correction to GCN 520 (IPN annulus for GRB000115)
  45. IPN annulus for GRB000115
  46. Second RXTE Observation of GRB 000115
  47. GRB991216, UBVRIJHK field photometry
  48. GRB991216 late optical observation
  49. Single IPN error box for GRB991229
  50. GCN resumes full operations
  51. GRB 991216 VLBA Observations
  52. BEPPOSAX GRBM Localization of GRB991226
  53. IPN error boxes for GRB991229
  54. GRB 991216: J band spectrophotometry
  55. GRB 991216: Detection of the Host and/or Absorber Galaxy
  56. IPN localization of GRB991226
  57. Single IPN error box for GRB991221
  58. IPN error boxes for GRB991221
  59. GRB 991216 RXTE ASM Observations
  60. IPN error box for GRB991216
  61. GRB 991216: Updated BATSE parameters
  62. Lowell/Perkins observation of GRB 991216
  63. GRB 991217 (SAX J2303.2+0015) Optical observations
  64. GRB991217/SAX J2303.2+0015, optical observations
  65. Chandra observation of the X-ray afterglow of GRB991216
  66. GRB 991216, optical observations
  67. GRB 991216 Optical Observations
  68. GRB 991216 Optical spectroscopy/imaging
  69. VLT spectra of GRB991216
  70. GRB991216 Optical and IR observations
  71. K observations of GRB991216
  72. SAX J2303.2+0015 Optical observations
  73. IR observations of GRB991216
  74. GRB991216 radio observations
  75. GRB991216 radio observations
  76. GRB991216 Spectroscopy
  77. Lowell/Perkins observation of GRB 991216
  78. GRB991216, optical observations
  79. GRB991216 Optical and infrared observations of Beethoven Burst
  80. Refined IPN localization of GRB991216
  81. GRB 991216 Radio Observations
  82. GRB 991217
  83. GRB 991208 Keck Spectroscopy
  84. GRB 991208 Infrared Detection
  85. GRB991216
  86. GRB 991216--Summary of RXTE Observations
  87. GRB 991216 Optical Observations
  88. GRB 991216, optical observations
  89. GRB 991208 SAO-RAS Spectroscopy
  90. SAX J2303.2+0015: an x-ray/GRB?
  91. GRB 991216, Optical Transient
  92. GRB 991216, Optical Afterglow
  93. GRB991216 ('Beethoven Burst') B, R, and K Observations
  94. GRB 991216: Comparison with DPOSS images
  95. GRB991216, infrared observations
  96. GRB991216 Optical Observations
  97. GRB 991208 optical observations
  98. Lowell/Perkins observation of GRB 991216
  99. GRB 991216 Optical Observation
  100. GRB 991208 Keck Spectroscopy

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