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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"

31633 results found.

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

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