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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"

98 results found.

  1. GRB 181003A: Swift/UVOT Upper Limits
  2. Swift triggered on SAX J1806.5-221
  3. GRB 160409A found in Swift BAT ground analysis
  4. Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
  5. Swift detection of SAX J1808.4-3658
  6. Swift detection of SAX J1712.6-3739
  7. Swift-BAT trigger 536502 is not astrophysical
  8. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  9. Swift-BAT trigger 535733 is not astrophysical
  10. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  11. SAX J1818.6-1703: Swift detection (trigger 306379)
  12. UVOT observations of SAXJ1810.8-2609
  13. Swift detection of a outburst from SAX J1810.8-2609
  14. GRB070223: Swift/UVOT refined analysis
  15. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  16. BeppoSAX GRB : GRB020409
  17. GRB020322: Candidate Optical Afterglow
  18. Bepposax GRB020322 The second springtime BSAX GRB
  19. GRB 011211 Optical Observations: Likely Afterglow
  20. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  21. GRB011121: BeppoSAX-WFC refined positions
  22. BEPPOSAX GRB011121
  23. The X-ray Flash 011030 ('GRB 011030')
  24. IPN triangulation of GRB010629
  25. Support extension to the BeppoSAX mission
  26. GRB010222: possible optical counterpart
  27. GRB010222
  28. GRB 010214, Optical Observations
  29. GRB000528, Radio Observations
  30. IPN triangulation of GRB000516
  31. BeppoSAX GRB000424
  32. GRB000419 [IPN Position]
  33. 1SAXJ1715.0-7134 refined position
  34. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  35. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  36. Budget cuts in BeppoSAX operations: impact on GRB observations
  37. GRB000226 [IPN Position]
  38. GRB 000210: BATSE Observations
  39. GRB000210, Radio Observations
  40. SAX_WFC_GRB_NOTICE
  41. SAX_WFC_GRB_NOTICE
  42. GCN resumes full operations
  43. IPN error box for GRB991216
  44. GRB 991217 (SAX J2303.2+0015) Optical observations
  45. GRB991217/SAX J2303.2+0015, optical observations
  46. SAX J2303.2+0015 Optical observations
  47. GRB 991217 (SAX J2303.2+0015) Optical observations
  48. GRB 991217
  49. SAX J2303.2+0015: an x-ray/GRB?
  50. BeppoSAX NFI Observation of GRB991106
  51. GRB 991105: BATSE Observations
  52. BeppoSAX refined position for GRB991106
  53. GRB991105: SAX-GRBM/-WFC detection
  54. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  55. GRB ALERT: GRB991105
  56. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  57. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  58. GRB990806 BeppoSAX follow up
  59. GRB 990712
  60. Infrared and Optical Observations of GRB990705
  61. GRB990704: SAX-NFI results summary
  62. GRB 990704 X-ray Observations
  63. GRB990705: Intriguing Positional Coincidences
  64. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  65. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  66. Optical report on X-ray/GRB transient
  67. BeppoSAX: A new fast X-ray transient
  68. GRB990123, Probability of gravitational lensing
  69. GRB990123 IPN annulus
  70. GRB990123, refined SAX-WFC position
  71. GRB 981226 Optical Observations
  72. GRB981226 BeppoSAX follow up
  73. GRB980425: X-ray revised positions
  74. GRB980519, Optical Observations
  75. GRB980703, Host galaxy multicolor photometry
  76. GRB 980703 (NFI observations)
  77. BeppoSAX NFI observations of GRB 980703
  78. GRB980703
  79. GRB980613, optical observations
  80. GRB 980613 Optical Observations
  81. GRB980613 BeppoSAX-NFI follow up
  82. GRB980613, BeppoSAX WFC positions
  83. GRB980519 IPN POSITION
  84. GRB980515: SAX-WFC updated position
  85. BSAX Observations of GRB980425 field
  86. GRB980425 BATSE observations
  87. SAX J0840.7+2248 Optical Observations
  88. report on BSAX observations of GRB980425
  89. GRB980329 IPN annulus
  90. GRB980329 near-IR observations
  91. GRB980329 near-IR observations
  92. GRB980329 near IR observations
  93. GRB980329 optical observations
  94. Optical Observations for GRB 971227
  95. GRB 971227: Optical observations
  96. GRB971214: Optical Observations and Calibrations
  97. Optical Observations of GRB 971214 at Keck
  98. GRB 971214: USNOFS Observations Summary

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