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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"

37438 results found.

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

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