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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"

3821 results found.

  1. GRB 070201: clarification on localization and Konus-Wind spectra
  2. IPN localization of very intense short GRB 070201
  3. GRB 070208: Swift detection of a burst
  4. GRB 070125: further AAVSO optical observations
  5. GRB 070125: Continued P60 Observations
  6. GRB 070110: Continued Detection and Request for Ground Followup
  7. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  8. Retractions of previous Swift-BAT triggers
  9. GRB061222a: optical observations
  10. GRB 061222B: MITSuME Akeno optical upper limits
  11. GRB 061222A: Prompt ROTSE-III Optical Limits
  12. GRB 061201: Magellan Redshift of nearby Abell cluster
  13. Swift-BAT Trigger 250908 is a Cosmic Ray Shower event
  14. GRB061121, optical observation
  15. GRB 061121: Swift detection of a bright burst with an optical counterpart
  16. GRB061019: second epoch CrAO observations
  17. GRB 061028: Swift/XRT Astrometry Correction
  18. GRB 061028: Optical R passband observations
  19. GRB 061028: Futher P200 Observations
  20. GRB 061028: Swift/UVOT Observations
  21. GRB 061028: Swift detection of a burst
  22. GRB 061027: Swift detection of a possible burst
  23. GRB061019: optical observations
  24. GRB 061019: SMARTS afterglow confirmation
  25. GRB 061019: REM K-band candidate afterglow
  26. GRB061019: Swift/XRT position
  27. GRB 061007: Suzaku/WAM observation of the prompt emission
  28. GRB 061007: Swift-BAT refined analysis
  29. GRB 061007: Swift detection of a burst with an optical counterpart
  30. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  31. GRB 061002: Swift detection of a burst
  32. GRB 060929: TNG K-band observations
  33. GRB060929: Optical limit
  34. GRB 060729: An update on the late-time Swift observations
  35. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  36. GRB 060926: Swift detection of a burst
  37. GRB 060923C: Keck Observations
  38. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  39. GRB 060919, Swift-BAT refined analysis
  40. GRB060904b optical detections (delayed report due to internet outage)
  41. GRB 060904B: RTT150 optical observations
  42. Two bright bursts from SGR 1806-20 detected with IBAS
  43. GRB 060825: VLA observations
  44. GRB060729: analysis of XMM-Newton observation
  45. GRB 060813: Swift XRT refined analysis
  46. Image of the dust-scattering halo around SGR 1806-20
  47. Second VLA limit on new radio point source in SGR 1806-20
  48. A dust-scattering halo detected around SGR 1806-20
  49. GRB060714: optical observations
  50. GRB060807: Optical limiting magnitudes
  51. VLA Upper Limit on Outburst of SGR 1806-20
  52. GRB060806 is similar to previous activity of SGR1806-20
  53. GRB 060728: Upper limits of the X-ray emission
  54. GRB 060729: Swift/UVOT Detections
  55. GRB 060729: Swift/UVOT Observations
  56. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  57. GRB 060728, SMARTS optical/IR observations
  58. GRB060614 ATCA Radio Limits
  59. GRB060526: optical observations
  60. GRB 060515: Upper Limit on Host Galaxy
  61. GRB050124: Possible Host Galaxy
  62. GRB 060614: Swift/UVOT Observations
  63. BAT Trigger #214277 is SGR 1900+14
  64. GCN 060607: Swift-UVOT obswervations.
  65. GRB 060607: REM NIR afterglow
  66. GRB 060607: Swift detection of a burst with bright optical counterpart
  67. GRB 060522: PROMPT Optical Limits
  68. GRB 060604A: ROTSE-III Optical Limits
  69. GRB 060526: RTT150 optical observations
  70. GRB 060526: RTT150 optical observations
  71. GRB 060526: Watcher Observations
  72. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  73. GRB 060515: Swift/XRT Team refined analysis
  74. GRB 060515: Swift/XRT position
  75. GRB 060515: TAROT optical observation
  76. GRB 060515: ROTSE-III Optical Limits
  77. GRB 060428a, SMARTS optical/IR afterglow detection
  78. GRB060418: Swift XRT Team Further Refined Analysis
  79. GRB060424: optical afterglow detection
  80. GRB 060421: TTT Observations
  81. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  82. SGR 1900+14: Swift detection of an outburst
  83. SGR 1900+14: BAT observations
  84. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  85. GRB060331: Swift/UVOT upper limits
  86. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  87. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  88. SGR 1900+14: Swift-BAT detection of a bright outburst
  89. SGR 1900+14: CORRECTION to GCN 4923
  90. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  91. SGR 1900+14: Swift detection of renewed activity
  92. GRB 060223B: Swift XRT possible afterglow
  93. GRB 060218: rebrightening
  94. GRB 060218: Likely an underluminous GRB
  95. GRB 060211A: Further refined analysis of the Swift burst
  96. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  97. GRB 060211B: Swift/BAT refined analysis
  98. GRB 060211A: Swift XRT Team Refined Analysis
  99. GRB 060211: Swift detection of a long burst
  100. GRB060206: Swift-BAT detection of a burst

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