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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"

42747 results found.

  1. GRB 000301C, Optical Observation
  2. GRB000301C, optical observations
  3. GRB000301C 250 GHz detection
  4. GRB 000301C R-band observation
  5. GRB 000301C, Optical Observation
  6. GRB000301C, near-infrared observations (JHK' photometry)
  7. GRB 000301C: OT confirmed
  8. GRB000301c optical observations
  9. GRB 000301A, Radio Observations
  10. GRB000301C, optical observations
  11. GRB000301c, near-infrared observations
  12. GRB000301C
  13. GRB 000301C : Optical Candidate
  14. GRB000301C: RXTE/ASM and IPN localizations
  15. GRB000301A [IPN Position]
  16. GRB000226 [IPN Position]
  17. HST Observations of GRB 990712
  18. GRB 000214 near-IR observations
  19. GRB 000115 Optical observations
  20. GRB 000214, Radio Observations
  21. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  22. GRB000210, Radio Observations
  23. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  24. GRB 000115, BVRI field photometry
  25. GRB000214: BeppoSAX GRBM and WFC Detection
  26. IPN annulus for GRB000214
  27. Optical observations of GRB000210
  28. GRB000210 X-ray afterglow
  29. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  30. GRB 000210: BATSE Observations
  31. Correction to Chandra Position of GRB000210 afterglow
  32. GRB000210, Radio Observations
  33. Chandra Observations of GRB000210 X-ray Afterglow
  34. IPN triangulation of GRB000210
  35. GRB000210: possible afterglow detection with BeppoSAX NFI
  36. GRB000201, Radio Observations
  37. GRB000210: BeppoSAX GRBM and WFC Detection
  38. Optical observations of GRB000131
  39. GRB000201 Optical Observations
  40. GRB 000201: TAROT optical observations
  41. GRB 000131 Optical Observations
  42. GRB000126 Optical Observations
  43. GRB 991208, radio observations
  44. BATSE+IPN location of GRB000131
  45. IPN localization of GRB000131
  46. GRB 000126, optical observations
  47. GRB000126, optical observations
  48. IPN localization of GRB000126
  49. GRB 000115 Optical observations
  50. BATSE Observations of GRB000115
  51. IPN annulus for GRB000115
  52. Second RXTE Observation of GRB 000115
  53. GRB991216, UBVRIJHK field photometry
  54. GRB991216 late optical observation
  55. Single IPN error box for GRB991229
  56. GCN resumes full operations
  57. GRB 991216 VLBA Observations
  58. BEPPOSAX GRBM Localization of GRB991226
  59. IPN error boxes for GRB991229
  60. GRB 991216: J band spectrophotometry
  61. GRB 991216: Detection of the Host and/or Absorber Galaxy
  62. IPN localization of GRB991226
  63. Single IPN error box for GRB991221
  64. IPN error boxes for GRB991221
  65. GRB 991216 RXTE ASM Observations
  66. IPN error box for GRB991216
  67. Lowell/Perkins observation of GRB 991216
  68. GRB 991217 (SAX J2303.2+0015) Optical observations
  69. GRB991217/SAX J2303.2+0015, optical observations
  70. Chandra observation of the X-ray afterglow of GRB991216
  71. GRB 991216, optical observations
  72. GRB 991216 Optical Observations
  73. GRB 991216 Optical spectroscopy/imaging
  74. VLT spectra of GRB991216
  75. GRB991216 Optical and IR observations
  76. K observations of GRB991216
  77. IR observations of GRB991216
  78. GRB991216 radio observations
  79. GRB 991217 (SAX J2303.2+0015) Optical observations
  80. GRB991216 radio observations
  81. GRB991216 Spectroscopy
  82. Lowell/Perkins observation of GRB 991216
  83. GRB991216, optical observations
  84. GRB991216 Optical and infrared observations of Beethoven Burst
  85. Refined IPN localization of GRB991216
  86. GRB 991216 Radio Observations
  87. GRB 991208 Keck Spectroscopy
  88. GRB 991208 Infrared Detection
  89. GRB991216
  90. GRB 991216--Summary of RXTE Observations
  91. GRB 991216 Optical Observations
  92. GRB 991216, optical observations
  93. GRB 991208 SAO-RAS Spectroscopy
  94. SAX J2303.2+0015: an x-ray/GRB?
  95. GRB 991216, Optical Transient
  96. GRB 991216, Optical Afterglow
  97. GRB991216 ('Beethoven Burst') B, R, and K Observations
  98. GRB 991216: Comparison with DPOSS images
  99. GRB991216, infrared observations
  100. GRB991216 Optical Observations

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