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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"

19424 results found.

  1. GRB000607, Radio Observations
  2. GRB000604 - Optical observations
  3. GRB000604, optical observations
  4. GRB000528, optical observations at ESO
  5. GRB 000418: Detection of the Host Galaxy
  6. GRB000604, optical observations, comparison with DPOSS
  7. GRB000604 [IPN Position]
  8. GRB000528, Radio Observations
  9. X-ray Afterglow of GRB 000529
  10. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  11. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  12. GRB000519: Optical observations
  13. GRB 000528 - WFC measurements
  14. GRB000528: BeppoSAX GRBM observations
  15. GRB000519, BVRI field photometry
  16. IPN triangulation of GRB000519
  17. GRB000508B, optical photometry
  18. GRB000508B, BVR field photometry
  19. Possible GRB-related phenomenon
  20. RXTE/ASM and IPN localization of GRB 000508B
  21. GRB000424, UBVRI field photometry
  22. GRB000418, UBVRI field photometry update
  23. The redshift of GRB 000418
  24. GRB000424, optical observations
  25. GRB 000429, optical observation
  26. GRB 000429, UBVRI field photometry
  27. GRB 000418, UBVRI field photometry
  28. GRB 000418, optical observation
  29. GRB000424 Optical Observations
  30. GRB 000418, Optical Observation
  31. Correction to IPN error box for GRB000419
  32. IPN error box for GRB000418
  33. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  34. GRB 000408, optical observations
  35. GRB 991208, UBVRI field photometry
  36. GRB000408, lotis optical observations
  37. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  38. GRB000408 [IPN Position]
  39. GRB000301C - Addendum to GCN 623
  40. GRB 000326: Optical Observations
  41. GRB000326, Radio observations
  42. GRB000315 [IPN Positions]
  43. GRB000313, Radio observations
  44. GRB 000313 - optical transient in the BATSE error box
  45. GRB 000307, BVRI Field Photometry
  46. GRB 000301C: HST/STIS CCD Imaging of the field
  47. IPN error box for GRB000307
  48. GRB000301C, optical R-band observations
  49. GRB000301c - R photometry and nearby faint source confirmation
  50. GRB 000301C Optical Observations
  51. GRB 000301C: K' Observations
  52. GRB000301C - Host galaxy not detected in R (?)
  53. Optical observations of GRB000301c
  54. GRB000301C, Radio observations
  55. GRB000301C, Radio observations
  56. GRB 000301c near-IR observations
  57. GRB 000301C, UBVRI field photometry
  58. GRB000301C, near-infrared observations (JHK' photometry)
  59. GRB 000301C: OT confirmed
  60. GRB000301c optical observations
  61. GRB000301c, near-infrared observations
  62. GRB000301C
  63. GRB 000301C : Optical Candidate
  64. GRB000301C: RXTE/ASM and IPN localizations
  65. GRB000226 [IPN Position]
  66. HST Observations of GRB 990712
  67. GRB 000214 near-IR observations
  68. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  69. GRB000210, Radio Observations
  70. GRB 000115, BVRI field photometry
  71. GRB000214: BeppoSAX GRBM and WFC Detection
  72. Optical observations of GRB000210
  73. GRB000210 X-ray afterglow
  74. GRB000214: X-ray afterglow candidate
  75. GRB000214 refined BeppoSAX-WFC position
  76. GRB 000210: BATSE Observations
  77. Optical observations of the Chandra X-ray source for GRB000210
  78. GRB000210, Radio Observations
  79. GRB000201, Radio Observations
  80. GRB000210: BeppoSAX GRBM and WFC Detection
  81. Optical observations of GRB000131
  82. GRB000201 Optical Observations
  83. GRB 000201: TAROT optical observations
  84. IPN localization of GRB000131
  85. GRB 000126, optical observations
  86. IPN localization of GRB000126
  87. BATSE Observations of GRB000115
  88. GRB991216, UBVRIJHK field photometry
  89. GCN resumes full operations
  90. IPN error boxes for GRB991229
  91. GRB 991216: Detection of the Host and/or Absorber Galaxy
  92. IPN error boxes for GRB991221
  93. IPN error box for GRB991216
  94. GRB 991217 (SAX J2303.2+0015) Optical observations
  95. Chandra observation of the X-ray afterglow of GRB991216
  96. GRB 991216, optical observations
  97. GRB 991216 Optical spectroscopy/imaging
  98. GRB991216 Optical and IR observations
  99. SAX J2303.2+0015 Optical observations
  100. IR observations of GRB991216

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