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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"

32501 results found.

  1. Optical observations of GRB000210
  2. GRB000210 X-ray afterglow
  3. GRB 000210: BATSE Observations
  4. Correction to Chandra Position of GRB000210 afterglow
  5. Optical observations of the Chandra X-ray source for GRB000210
  6. GRB000210, Radio Observations
  7. Optical candidate for GRB000210
  8. Chandra Observations of GRB000210 X-ray Afterglow
  9. IPN triangulation of GRB000210
  10. GRB000201, Radio Observations
  11. Optical observations of GRB000131
  12. GRB000201 Optical Observations
  13. GRB 000131 Optical Observations
  14. GRB000126 Optical Observations
  15. GRB 991208, radio observations
  16. BATSE+IPN location of GRB000131
  17. GRB 000126, optical observations
  18. GRB000126, optical observations
  19. BATSE location of GRB000126
  20. GRB 000115 Optical observations
  21. BATSE Observations of GRB000115
  22. Correction to GCN 520 (IPN annulus for GRB000115)
  23. IPN annulus for GRB000115
  24. GRB991216, UBVRIJHK field photometry
  25. GRB991216 late optical observation
  26. Single IPN error box for GRB991229
  27. GCN resumes full operations
  28. GRB 991216 VLBA Observations
  29. BEPPOSAX GRBM Localization of GRB991226
  30. GRB 991216: J band spectrophotometry
  31. GRB 991216: Detection of the Host and/or Absorber Galaxy
  32. Single IPN error box for GRB991221
  33. GRB 991216 RXTE ASM Observations
  34. IPN error box for GRB991216
  35. Lowell/Perkins observation of GRB 991216
  36. GRB 991217 (SAX J2303.2+0015) Optical observations
  37. GRB991217/SAX J2303.2+0015, optical observations
  38. Chandra observation of the X-ray afterglow of GRB991216
  39. GRB 991216, optical observations
  40. GRB 991216 Optical Observations
  41. GRB 991216 Optical spectroscopy/imaging
  42. VLT spectra of GRB991216
  43. GRB991216 Optical and IR observations
  44. SAX J2303.2+0015 Optical observations
  45. IR observations of GRB991216
  46. GRB991216 radio observations
  47. GRB 991217 (SAX J2303.2+0015) Optical observations
  48. GRB991216 radio observations
  49. Lowell/Perkins observation of GRB 991216
  50. GRB991216, optical observations
  51. Refined IPN localization of GRB991216
  52. GRB 991216 Radio Observations
  53. GRB 991208 Keck Spectroscopy
  54. GRB 991208 Infrared Detection
  55. GRB991216
  56. GRB 991216--Summary of RXTE Observations
  57. GRB 991216 Optical Observations
  58. GRB 991216, optical observations
  59. GRB 991208 SAO-RAS Spectroscopy
  60. GRB 991216, Optical Transient
  61. GRB 991216, Optical Afterglow
  62. GRB991216 ('Beethoven Burst') B, R, and K Observations
  63. GRB 991216: Comparison with DPOSS images
  64. GRB 991208 optical observations
  65. Lowell/Perkins observation of GRB 991216
  66. GRB 991216 Optical Observation
  67. GRB 991208 Keck Spectroscopy
  68. R-band Observations of GRB991208 at TNG
  69. GRB991208, optical observations
  70. GRB 991208 Keck Spectroscopy
  71. GRB991208 - millimeter detection
  72. GRB 991208, Optical Observation
  73. GRB991208 15-GHz observations
  74. GRB991208, optical observations
  75. GRB 991208 - OVRO detection
  76. GRB 991208 Optical Decay
  77. GRB 991208 optical observations
  78. GRB 991208 optical observations
  79. GRB 991208: Radio Observations
  80. Optical Observations of GRB991105
  81. GRB991106: BeppoSAX/BATSE results
  82. GRB 991106, optical observations
  83. GRB991106, near-infrared observations
  84. BeppoSAX NFI Observation of GRB991106
  85. GRB 991106, radio observations
  86. GRB 991105: BATSE Observations
  87. IPN localization of GRB991105
  88. GRB 991106 Optical Observations
  89. GRB 991105, optical observations
  90. GRB991106, optical observation at SAO-RAS
  91. GRB 991106, LOTIS Optical Observations
  92. GRB 991106, optical observations
  93. Revised BeppoSAX WFC position of GRB991105
  94. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  95. GRB 991014, Optical Observations
  96. GRB 991014 - BeppoSAX NFI observations
  97. GRB 991014, Optical Observations
  98. GRB 991014, Optical Observations
  99. GRB 991014, optical observations
  100. Super-LOTIS optical observation of GRB991014

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