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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"

31737 results found.

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

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