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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"

41617 results found.

  1. GRB000301C optical observations
  2. GRB000301C, near-infrared observations (JHK' imaging)
  3. GRB 000301c near-IR observations
  4. GRB 000301C, Optical Color
  5. GRB000301C, Optical Spectroscopy
  6. GRB 000301C, UBVRI field photometry
  7. GRB000301C, optical observations
  8. GRB000301C 250 GHz detection
  9. GRB 000301C R-band observation
  10. GRB 000301C, Optical Observation
  11. GRB000301C, near-infrared observations (JHK' photometry)
  12. GRB 000301C: OT confirmed
  13. GRB000301c optical observations
  14. GRB 000301A, Radio Observations
  15. GRB000301C, optical observations
  16. GRB000301c, near-infrared observations
  17. GRB000301C
  18. GRB 000301C : Optical Candidate
  19. Radio observations of the error box of GRB000301A
  20. GRB000301C: RXTE/ASM and IPN localizations
  21. HST Observations of GRB 990712
  22. GRB 000214 near-IR observations
  23. GRB 000115 Optical observations
  24. GRB 000214, Radio Observations
  25. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  26. GRB000210, Radio Observations
  27. GRB 000115, BVRI field photometry
  28. GRB000214: BeppoSAX GRBM and WFC Detection
  29. IPN annulus for GRB000214
  30. Optical observations of GRB000210
  31. GRB000210 X-ray afterglow
  32. GRB000214: X-ray afterglow candidate
  33. GRB000214 refined BeppoSAX-WFC position
  34. GRB 000210: BATSE Observations
  35. Correction to Chandra Position of GRB000210 afterglow
  36. Optical observations of the Chandra X-ray source for GRB000210
  37. GRB000210, Radio Observations
  38. Optical candidate for GRB000210
  39. Chandra Observations of GRB000210 X-ray Afterglow
  40. IPN triangulation of GRB000210
  41. GRB000210: possible afterglow detection with BeppoSAX NFI
  42. GRB000201, Radio Observations
  43. GRB000210: BeppoSAX GRBM and WFC Detection
  44. Optical observations of GRB000131
  45. GRB000201 Optical Observations
  46. GRB 000201: TAROT optical observations
  47. GRB 000131 Optical Observations
  48. GRB000126 Optical Observations
  49. GRB 991208, radio observations
  50. BATSE+IPN location of GRB000131
  51. GRB 000126, optical observations
  52. GRB000126, optical observations
  53. BATSE location of GRB000126
  54. GRB 000115 Optical observations
  55. BATSE Observations of GRB000115
  56. IPN annulus for GRB000115
  57. GRB991216, UBVRIJHK field photometry
  58. GRB991216 late optical observation
  59. GCN resumes full operations
  60. GRB 991216 VLBA Observations
  61. IPN error boxes for GRB991229
  62. GRB 991216: J band spectrophotometry
  63. GRB 991216: Detection of the Host and/or Absorber Galaxy
  64. GRB 991216 RXTE ASM Observations
  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. K observations of GRB991216
  75. SAX J2303.2+0015 Optical observations
  76. IR observations of GRB991216
  77. GRB991216 radio observations
  78. GRB 991217 (SAX J2303.2+0015) Optical observations
  79. GRB991216 radio observations
  80. GRB991216 Spectroscopy
  81. Lowell/Perkins observation of GRB 991216
  82. GRB991216, optical observations
  83. GRB991216 Optical and infrared observations of Beethoven Burst
  84. GRB 991216 Radio Observations
  85. GRB 991208 Keck Spectroscopy
  86. GRB 991208 Infrared Detection
  87. GRB991216
  88. GRB 991216--Summary of RXTE Observations
  89. GRB 991216 Optical Observations
  90. GRB 991216, optical observations
  91. GRB 991208 SAO-RAS Spectroscopy
  92. SAX J2303.2+0015: an x-ray/GRB?
  93. GRB 991216, Optical Transient
  94. GRB 991216, Optical Afterglow
  95. GRB991216 ('Beethoven Burst') B, R, and K Observations
  96. GRB 991216: Comparison with DPOSS images
  97. GRB991216, infrared observations
  98. GRB991216 Optical Observations
  99. GRB 991208 optical observations
  100. Lowell/Perkins observation of GRB 991216

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