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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"

36301 results found.

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

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