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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"

36793 results found.

  1. GRB 000313 - optical transient in the BATSE error box
  2. GRB000301C - B and R photometry
  3. GRB000301C - R photometry
  4. GRB 000307, Optical Observations
  5. GRB 000307, BVRI Field Photometry
  6. GRB 000301C: Optical Spectrum and Redshift
  7. GRB 000301C: Optical Spectrum and Redshift
  8. GRB 000301C: A Precise Redshift Determination
  9. GRB 000301C, Optical Observation
  10. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  11. GRB 000301C: HST/STIS CCD Imaging of the field
  12. IPN error box for GRB000307
  13. GRB 000301c: K' observations
  14. GRB000301C, optical R-band observations
  15. GRB000301c - R photometry and nearby faint source confirmation
  16. GRB 000301C, Optical Observation
  17. GRB 000301c: K' observations
  18. GRB 000301C Optical Observations
  19. GRB 000301C: K' Observations
  20. GRB000301C - Host galaxy not detected in R (?)
  21. GRB000301C optical observations
  22. GRB 000301c near-IR observations
  23. GRB 000301C, Optical Color
  24. GRB000301C, Optical Spectroscopy
  25. GRB 000301C, UBVRI field photometry
  26. GRB 000301C, Optical Observation
  27. GRB000301C 250 GHz detection
  28. GRB 000301C R-band observation
  29. GRB 000301C, Optical Observation
  30. GRB000301C, near-infrared observations (JHK' photometry)
  31. GRB 000301C: OT confirmed
  32. GRB000301c optical observations
  33. GRB 000301A, Radio Observations
  34. GRB000301C, optical observations
  35. GRB000301c, near-infrared observations
  36. GRB000301C
  37. GRB 000301C : Optical Candidate
  38. GRB000301C: RXTE/ASM and IPN localizations
  39. GRB000226 [IPN Position]
  40. HST Observations of GRB 990712
  41. GRB 000214 near-IR observations
  42. GRB 000115 Optical observations
  43. GRB 000214, Radio Observations
  44. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  45. GRB 000115, BVRI field photometry
  46. IPN annulus for GRB000214
  47. BATSE GRB trigger criterion changed
  48. GRB000210 X-ray afterglow
  49. GRB000214: X-ray afterglow candidate
  50. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  51. GRB 000210: BATSE Observations
  52. Optical observations of the Chandra X-ray source for GRB000210
  53. Chandra Observations of GRB000210 X-ray Afterglow
  54. IPN triangulation of GRB000210
  55. GRB 000201: TAROT optical observations
  56. GRB 000131 Optical Observations
  57. GRB000126 Optical Observations
  58. BATSE GRB trigger criteria changed
  59. GRB 991208, radio observations
  60. BATSE+IPN location of GRB000131
  61. IPN localization of GRB000131
  62. GRB 000126, optical observations
  63. GRB000126, optical observations
  64. BATSE location of GRB000126
  65. IPN localization of GRB000126
  66. GRB 000115 Optical observations
  67. BATSE Observations of GRB000115
  68. Second RXTE Observation of GRB 000115
  69. GRB991216, UBVRIJHK field photometry
  70. Single IPN error box for GRB991229
  71. GRB 991216 VLBA Observations
  72. BEPPOSAX GRBM Localization of GRB991226
  73. IPN error boxes for GRB991229
  74. GRB 991216: J band spectrophotometry
  75. GRB 991216: Detection of the Host and/or Absorber Galaxy
  76. IPN localization of GRB991226
  77. Single IPN error box for GRB991221
  78. IPN error boxes for GRB991221
  79. GRB 991216 RXTE ASM Observations
  80. IPN error box for GRB991216
  81. GRB 991216: Updated BATSE parameters
  82. Lowell/Perkins observation of GRB 991216
  83. GRB 991217 (SAX J2303.2+0015) Optical observations
  84. Chandra observation of the X-ray afterglow of GRB991216
  85. GRB 991216, optical observations
  86. GRB 991216 Optical Observations
  87. GRB 991216 Optical spectroscopy/imaging
  88. K observations of GRB991216
  89. GRB 991217 (SAX J2303.2+0015) Optical observations
  90. GRB991216 Spectroscopy
  91. Lowell/Perkins observation of GRB 991216
  92. GRB991216, optical observations
  93. Refined IPN localization of GRB991216
  94. GRB 991216 Radio Observations
  95. GRB 991217
  96. GRB 991208 Keck Spectroscopy
  97. GRB 991208 Infrared Detection
  98. GRB 991216--Summary of RXTE Observations
  99. GRB 991216 Optical Observations
  100. GRB 991216, optical observations

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