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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"

31731 results found.

  1. GRB 000301C Optical Observations
  2. GRB 000301C: K' Observations
  3. GRB000301C OT candidate optical observations
  4. Optical observations of GRB000301c
  5. GRB000301C, Radio observations
  6. GRB000301C, Radio observations
  7. GRB000301C, near-infrared observations (JHK' imaging)
  8. GRB 000301C, Optical Color
  9. GRB 000301C, UBVRI field photometry
  10. GRB 000301C, Optical Observation
  11. GRB000301C, optical observations
  12. GRB000301C 250 GHz detection
  13. GRB 000301C R-band observation
  14. GRB 000301C, Optical Observation
  15. GRB000301C, near-infrared observations (JHK' photometry)
  16. GRB 000301C: OT confirmed
  17. GRB000301c optical observations
  18. GRB 000301A, Radio Observations
  19. GRB000301C, optical observations
  20. GRB000301c, near-infrared observations
  21. GRB000301C
  22. GRB 000301C : Optical Candidate
  23. Radio observations of the error box of GRB000301A
  24. HST Observations of GRB 990712
  25. GRB 000115 Optical observations
  26. GRB 000214, Radio Observations
  27. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  28. GRB000210, Radio Observations
  29. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  30. IPN annulus for GRB000214
  31. Optical observations of GRB000210
  32. GRB000210 X-ray afterglow
  33. GRB 000210: BATSE Observations
  34. Correction to Chandra Position of GRB000210 afterglow
  35. Optical observations of the Chandra X-ray source for GRB000210
  36. GRB000210, Radio Observations
  37. Optical candidate for GRB000210
  38. Chandra Observations of GRB000210 X-ray Afterglow
  39. IPN triangulation of GRB000210
  40. GRB000201, Radio Observations
  41. Optical observations of GRB000131
  42. GRB000201 Optical Observations
  43. GRB 000131 Optical Observations
  44. GRB000126 Optical Observations
  45. GRB 991208, radio observations
  46. BATSE+IPN location of GRB000131
  47. GRB 000126, optical observations
  48. GRB000126, optical observations
  49. BATSE location of GRB000126
  50. GRB 000115 Optical observations
  51. BATSE Observations of GRB000115
  52. Correction to GCN 520 (IPN annulus for GRB000115)
  53. IPN annulus for GRB000115
  54. GRB991216, UBVRIJHK field photometry
  55. GRB991216 late optical observation
  56. Single IPN error box for GRB991229
  57. GCN resumes full operations
  58. GRB 991216 VLBA Observations
  59. BEPPOSAX GRBM Localization of GRB991226
  60. GRB 991216: J band spectrophotometry
  61. GRB 991216: Detection of the Host and/or Absorber Galaxy
  62. Single IPN error box for GRB991221
  63. GRB 991216 RXTE ASM Observations
  64. IPN error box for GRB991216
  65. Lowell/Perkins observation of GRB 991216
  66. GRB 991217 (SAX J2303.2+0015) Optical observations
  67. GRB991217/SAX J2303.2+0015, optical observations
  68. Chandra observation of the X-ray afterglow of GRB991216
  69. GRB 991216, optical observations
  70. GRB 991216 Optical Observations
  71. GRB 991216 Optical spectroscopy/imaging
  72. VLT spectra of GRB991216
  73. GRB991216 Optical and IR observations
  74. SAX J2303.2+0015 Optical observations
  75. IR observations of GRB991216
  76. GRB991216 radio observations
  77. GRB 991217 (SAX J2303.2+0015) Optical observations
  78. GRB991216 radio observations
  79. Lowell/Perkins observation of GRB 991216
  80. GRB991216, optical observations
  81. Refined IPN localization of GRB991216
  82. GRB 991216 Radio Observations
  83. GRB 991208 Keck Spectroscopy
  84. GRB 991208 Infrared Detection
  85. GRB991216
  86. GRB 991216--Summary of RXTE Observations
  87. GRB 991216 Optical Observations
  88. GRB 991216, optical observations
  89. GRB 991208 SAO-RAS Spectroscopy
  90. GRB 991216, Optical Transient
  91. GRB 991216, Optical Afterglow
  92. GRB991216 ('Beethoven Burst') B, R, and K Observations
  93. GRB 991216: Comparison with DPOSS images
  94. GRB 991208 optical observations
  95. Lowell/Perkins observation of GRB 991216
  96. GRB 991216 Optical Observation
  97. GRB 991208 Keck Spectroscopy
  98. R-band Observations of GRB991208 at TNG
  99. GRB991208, optical observations
  100. GRB 991208 Keck Spectroscopy

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