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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"

36784 results found.

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

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