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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"
  1. GRB000301C - Host galaxy not detected in R (?)
  2. Optical observations of GRB000301c
  3. GRB000301C, Radio observations
  4. GRB000301C, Radio observations
  5. GRB000301C optical observations
  6. GRB000301C, near-infrared observations (JHK' imaging)
  7. GRB 000301c near-IR observations
  8. GRB 000301C, Optical Color
  9. GRB000301C, Optical Spectroscopy
  10. GRB 000301C, UBVRI field photometry
  11. GRB 000301C, Optical Observation
  12. GRB000301C, optical observations
  13. GRB000301C 250 GHz detection
  14. GRB 000301C R-band observation
  15. GRB 000301C, Optical Observation
  16. GRB000301C, near-infrared observations (JHK' photometry)
  17. GRB 000301C: OT confirmed
  18. GRB000301c optical observations
  19. GRB 000301A, Radio Observations
  20. GRB000301C, optical observations
  21. GRB000301c, near-infrared observations
  22. GRB000301C
  23. GRB 000301C : Optical Candidate
  24. Radio observations of the error box of GRB000301A
  25. GRB000301C: RXTE/ASM and IPN localizations
  26. GRB000301A [IPN Position]
  27. GRB000226 [IPN Position]
  28. HST Observations of GRB 990712
  29. GRB 000214 near-IR observations
  30. GRB 000115 Optical observations
  31. GRB 000214, Radio Observations
  32. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  33. GRB000210, Radio Observations
  34. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  35. GRB 000115, BVRI field photometry
  36. GRB000214: BeppoSAX GRBM and WFC Detection
  37. IPN annulus for GRB000214
  38. BATSE GRB trigger criterion changed
  39. Optical observations of GRB000210
  40. GRB000210 X-ray afterglow
  41. GRB000214: X-ray afterglow candidate
  42. GRB000214 refined BeppoSAX-WFC position
  43. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  44. GRB 000210: BATSE Observations
  45. Correction to Chandra Position of GRB000210 afterglow
  46. Optical observations of the Chandra X-ray source for GRB000210
  47. GRB000210, Radio Observations
  48. Optical candidate for GRB000210
  49. Chandra Observations of GRB000210 X-ray Afterglow
  50. IPN triangulation of GRB000210
  51. GRB000210: possible afterglow detection with BeppoSAX NFI
  52. GRB000201, Radio Observations
  53. GRB000210: BeppoSAX GRBM and WFC Detection
  54. SAX_WFC_GRB_NOTICE
  55. SAX_WFC_GRB_NOTICE
  56. Optical observations of GRB000131
  57. GRB000201 Optical Observations
  58. GRB 000201: TAROT optical observations
  59. GRB 000131 Optical Observations
  60. GRB000126 Optical Observations
  61. BATSE GRB trigger criteria changed
  62. GRB 991208, radio observations
  63. BATSE+IPN location of GRB000131
  64. IPN localization of GRB000131
  65. GRB 000126, optical observations
  66. GRB000126, optical observations
  67. BATSE location of GRB000126
  68. IPN localization of GRB000126
  69. GRB 000115 Optical observations
  70. BATSE Observations of GRB000115
  71. Correction to GCN 520 (IPN annulus for GRB000115)
  72. IPN annulus for GRB000115
  73. Second RXTE Observation of GRB 000115
  74. GRB991216, UBVRIJHK field photometry
  75. GRB991216 late optical observation
  76. Single IPN error box for GRB991229
  77. GCN resumes full operations
  78. GRB 991216 VLBA Observations
  79. BEPPOSAX GRBM Localization of GRB991226
  80. IPN error boxes for GRB991229
  81. GRB 991216: J band spectrophotometry
  82. GRB 991216: Detection of the Host and/or Absorber Galaxy
  83. IPN localization of GRB991226
  84. Single IPN error box for GRB991221
  85. IPN error boxes for GRB991221
  86. GRB 991216 RXTE ASM Observations
  87. IPN error box for GRB991216
  88. GRB 991216: Updated BATSE parameters
  89. Lowell/Perkins observation of GRB 991216
  90. GRB 991217 (SAX J2303.2+0015) Optical observations
  91. GRB991217/SAX J2303.2+0015, optical observations
  92. Chandra observation of the X-ray afterglow of GRB991216
  93. GRB 991216, optical observations
  94. GRB 991216 Optical Observations
  95. GRB 991216 Optical spectroscopy/imaging
  96. VLT spectra of GRB991216
  97. GRB991216 Optical and IR observations
  98. K observations of GRB991216
  99. SAX J2303.2+0015 Optical observations
  100. IR observations of GRB991216

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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