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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"

28712 results found.

  1. GRB000301c, near-infrared observations
  2. GRB000301C
  3. GRB 000301C : Optical Candidate
  4. Radio observations of the error box of GRB000301A
  5. HST Observations of GRB 990712
  6. GRB 000115 Optical observations
  7. GRB 000214, Radio Observations
  8. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  9. GRB000210, Radio Observations
  10. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  11. IPN annulus for GRB000214
  12. Optical observations of GRB000210
  13. GRB000210 X-ray afterglow
  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. GRB000201, Radio Observations
  22. Optical observations of GRB000131
  23. GRB000201 Optical Observations
  24. GRB 000131 Optical Observations
  25. GRB000126 Optical Observations
  26. GRB 991208, radio observations
  27. BATSE+IPN location of GRB000131
  28. GRB 000126, optical observations
  29. GRB000126, optical observations
  30. BATSE location of GRB000126
  31. GRB 000115 Optical observations
  32. BATSE Observations of GRB000115
  33. Correction to GCN 520 (IPN annulus for GRB000115)
  34. IPN annulus for GRB000115
  35. GRB991216, UBVRIJHK field photometry
  36. GRB991216 late optical observation
  37. Single IPN error box for GRB991229
  38. GCN resumes full operations
  39. GRB 991216 VLBA Observations
  40. BEPPOSAX GRBM Localization of GRB991226
  41. GRB 991216: J band spectrophotometry
  42. GRB 991216: Detection of the Host and/or Absorber Galaxy
  43. Single IPN error box for GRB991221
  44. GRB 991216 RXTE ASM Observations
  45. IPN error box for GRB991216
  46. Lowell/Perkins observation of GRB 991216
  47. GRB 991217 (SAX J2303.2+0015) Optical observations
  48. GRB991217/SAX J2303.2+0015, optical observations
  49. Chandra observation of the X-ray afterglow of GRB991216
  50. GRB 991216, optical observations
  51. GRB 991216 Optical Observations
  52. GRB 991216 Optical spectroscopy/imaging
  53. VLT spectra of GRB991216
  54. GRB991216 Optical and IR observations
  55. SAX J2303.2+0015 Optical observations
  56. IR observations of GRB991216
  57. GRB991216 radio observations
  58. GRB 991217 (SAX J2303.2+0015) Optical observations
  59. GRB991216 radio observations
  60. Lowell/Perkins observation of GRB 991216
  61. GRB991216, optical observations
  62. Refined IPN localization of GRB991216
  63. GRB 991216 Radio Observations
  64. GRB 991208 Keck Spectroscopy
  65. GRB 991208 Infrared Detection
  66. GRB991216
  67. GRB 991216--Summary of RXTE Observations
  68. GRB 991216 Optical Observations
  69. GRB 991216, optical observations
  70. GRB 991208 SAO-RAS Spectroscopy
  71. GRB 991216, Optical Transient
  72. GRB 991216, Optical Afterglow
  73. GRB991216 ('Beethoven Burst') B, R, and K Observations
  74. GRB 991216: Comparison with DPOSS images
  75. GRB 991208 optical observations
  76. Lowell/Perkins observation of GRB 991216
  77. GRB 991216 Optical Observation
  78. GRB 991208 Keck Spectroscopy
  79. R-band Observations of GRB991208 at TNG
  80. GRB991208, optical observations
  81. GRB 991208 Keck Spectroscopy
  82. GRB991208 - millimeter detection
  83. GRB 991208, Optical Observation
  84. GRB991208 15-GHz observations
  85. GRB991208, optical observations
  86. GRB 991208 - OVRO detection
  87. GRB 991208 Optical Decay
  88. GRB 991208 optical observations
  89. GRB 991208 optical observations
  90. GRB 991208: Radio Observations
  91. Optical Observations of GRB991105
  92. GRB991106: BeppoSAX/BATSE results
  93. GRB 991106, optical observations
  94. GRB991106, near-infrared observations
  95. BeppoSAX NFI Observation of GRB991106
  96. GRB 991106, radio observations
  97. GRB 991105: BATSE Observations
  98. IPN localization of GRB991105
  99. GRB 991106 Optical Observations
  100. GRB 991105, optical observations

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