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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"

41619 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. GRB000301C, optical observations
  10. GRB000301C 250 GHz detection
  11. GRB 000301C R-band observation
  12. GRB 000301C, Optical Observation
  13. GRB000301C, near-infrared observations (JHK' photometry)
  14. GRB 000301C: OT confirmed
  15. GRB000301c optical observations
  16. GRB 000301A, Radio Observations
  17. GRB000301C, optical observations
  18. GRB000301c, near-infrared observations
  19. GRB000301C
  20. GRB 000301C : Optical Candidate
  21. Radio observations of the error box of GRB000301A
  22. GRB000301C: RXTE/ASM and IPN localizations
  23. HST Observations of GRB 990712
  24. GRB 000214 near-IR observations
  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. GRB 000115, BVRI field photometry
  30. GRB000214: BeppoSAX GRBM and WFC Detection
  31. IPN annulus for GRB000214
  32. Optical observations of GRB000210
  33. GRB000210 X-ray afterglow
  34. GRB000214: X-ray afterglow candidate
  35. GRB000214 refined BeppoSAX-WFC position
  36. GRB 000210: BATSE Observations
  37. Correction to Chandra Position of GRB000210 afterglow
  38. Optical observations of the Chandra X-ray source for GRB000210
  39. GRB000210, Radio Observations
  40. Optical candidate for GRB000210
  41. Chandra Observations of GRB000210 X-ray Afterglow
  42. IPN triangulation of GRB000210
  43. GRB000210: possible afterglow detection with BeppoSAX NFI
  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. GRB 991208, radio observations
  52. BATSE+IPN location of GRB000131
  53. GRB 000126, optical observations
  54. GRB000126, optical observations
  55. BATSE location of GRB000126
  56. GRB 000115 Optical observations
  57. BATSE Observations of GRB000115
  58. IPN annulus for GRB000115
  59. GRB991216, UBVRIJHK field photometry
  60. GRB991216 late optical observation
  61. GCN resumes full operations
  62. GRB 991216 VLBA Observations
  63. IPN error boxes for GRB991229
  64. GRB 991216: J band spectrophotometry
  65. GRB 991216: Detection of the Host and/or Absorber Galaxy
  66. GRB 991216 RXTE ASM Observations
  67. Lowell/Perkins observation of GRB 991216
  68. GRB 991217 (SAX J2303.2+0015) Optical observations
  69. GRB991217/SAX J2303.2+0015, optical observations
  70. Chandra observation of the X-ray afterglow of GRB991216
  71. GRB 991216, optical observations
  72. GRB 991216 Optical Observations
  73. GRB 991216 Optical spectroscopy/imaging
  74. VLT spectra of GRB991216
  75. GRB991216 Optical and IR observations
  76. K observations of GRB991216
  77. SAX J2303.2+0015 Optical observations
  78. IR observations of GRB991216
  79. GRB991216 radio observations
  80. GRB 991217 (SAX J2303.2+0015) Optical observations
  81. GRB991216 radio observations
  82. GRB991216 Spectroscopy
  83. Lowell/Perkins observation of GRB 991216
  84. GRB991216, optical observations
  85. GRB991216 Optical and infrared observations of Beethoven Burst
  86. GRB 991216 Radio Observations
  87. GRB 991208 Keck Spectroscopy
  88. GRB 991208 Infrared Detection
  89. GRB991216
  90. GRB 991216--Summary of RXTE Observations
  91. GRB 991216 Optical Observations
  92. GRB 991216, optical observations
  93. GRB 991208 SAO-RAS Spectroscopy
  94. SAX J2303.2+0015: an x-ray/GRB?
  95. GRB 991216, Optical Transient
  96. GRB 991216, Optical Afterglow
  97. GRB991216 ('Beethoven Burst') B, R, and K Observations
  98. GRB 991216: Comparison with DPOSS images
  99. GRB991216, infrared observations
  100. GRB991216 Optical Observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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