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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"

24870 results found.

  1. The Hosts of GRB 980703 and GRB 971214
  2. GRB 000301C: Further Late-Time HST/STIS observations
  3. GRB000528: follow-up X-ray measurements and update of IPN annulus
  4. GRB980519, HST/STIS observations of the host galaxy
  5. GRB000604 optical non-detection
  6. GRB000604 - Optical observations
  7. GRB000604, optical observations
  8. GRB000528, optical observations at ESO
  9. GRB 000604 optical observations
  10. GRB 000418: Detection of the Host Galaxy
  11. GRB000604, optical observations, comparison with DPOSS
  12. GRB000528, Radio Observations
  13. X-ray Afterglow of GRB 000529
  14. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  15. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  16. GRB 000528 - WFC measurements
  17. GRB000519, BVRI field photometry
  18. IPN triangulation of GRB000519
  19. GRB000508B, optical photometry
  20. GRB000508B, BVR field photometry
  21. Possible GRB-related phenomenon
  22. RXTE/ASM and IPN localization of GRB 000508B
  23. GRB000424, UBVRI field photometry
  24. GRB000418, UBVRI field photometry update
  25. GRB000424, optical observations
  26. GRB 000429, optical observation
  27. GRB 000429, UBVRI field photometry
  28. GRB 000418, UBVRI field photometry
  29. GRB 000418, optical observation
  30. GRB 000418, Optical Observation
  31. GRB000418, near-infrared observations
  32. Correction to IPN error box for GRB000419
  33. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  34. GRB000416 BRJK observations
  35. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  36. GRB 000408, optical observations
  37. GRB 991208, UBVRI field photometry
  38. GRB000408, lotis optical observations
  39. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  40. GRB000301C - Addendum to GCN 623
  41. GRB 000323, optical observations
  42. GRB 000326: Optical Observations
  43. GRB000326, Radio observations
  44. GRB000313, Radio observations
  45. GRB 000313 - optical transient in the BATSE error box
  46. GRB 000307, Optical Observations
  47. GRB 000307, BVRI Field Photometry
  48. GRB 000301C: A Precise Redshift Determination
  49. GRB 000301C, Optical Observation
  50. GRB 000301C: HST/STIS CCD Imaging of the field
  51. IPN error box for GRB000307
  52. GRB000301C, optical R-band observations
  53. GRB 000301C Optical Observations
  54. GRB 000301C: K' Observations
  55. GRB000301C OT candidate optical observations
  56. GRB000301C - Host galaxy not detected in R (?)
  57. Optical observations of GRB000301c
  58. GRB000301C, Radio observations
  59. GRB000301C, Radio observations
  60. GRB000301C, near-infrared observations (JHK' imaging)
  61. GRB 000301c near-IR observations
  62. GRB 000301C, UBVRI field photometry
  63. GRB 000301C: OT confirmed
  64. GRB000301c optical observations
  65. GRB000301C, optical observations
  66. GRB000301C
  67. GRB 000301C : Optical Candidate
  68. GRB000301C: RXTE/ASM and IPN localizations
  69. GRB000226 [IPN Position]
  70. HST Observations of GRB 990712
  71. GRB 000214 near-IR observations
  72. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  73. GRB000210, Radio Observations
  74. GRB 000115, BVRI field photometry
  75. GRB000214: BeppoSAX GRBM and WFC Detection
  76. Optical observations of GRB000210
  77. GRB000210 X-ray afterglow
  78. GRB000214: X-ray afterglow candidate
  79. GRB000214 refined BeppoSAX-WFC position
  80. GRB 000210: BATSE Observations
  81. Optical observations of the Chandra X-ray source for GRB000210
  82. GRB000210, Radio Observations
  83. IPN triangulation of GRB000210
  84. GRB000210: possible afterglow detection with BeppoSAX NFI
  85. GRB000201, Radio Observations
  86. GRB000210: BeppoSAX GRBM and WFC Detection
  87. SAX_WFC_GRB_NOTICE
  88. SAX_WFC_GRB_NOTICE
  89. GRB000201 Optical Observations
  90. GRB 000201: TAROT optical observations
  91. GRB 991208, radio observations
  92. BATSE+IPN location of GRB000131
  93. IPN localization of GRB000131
  94. GRB 000126, optical observations
  95. BATSE Observations of GRB000115
  96. Second RXTE Observation of GRB 000115
  97. GRB991216, UBVRIJHK field photometry
  98. GCN resumes full operations
  99. GRB 991216 VLBA Observations
  100. GRB 991216: J band spectrophotometry

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