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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"

36789 results found.

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

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