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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"

3037 results found.

  1. GRB 060424: Refined analysis of the Swift-BAT burst
  2. GRB 060403: Swift detection of a burst
  3. GRB 060312: ROTSE-III Optical Limits
  4. Bright short hard GRB 060303: IPN localization and Konus spectrum
  5. GRB 060223B: Swift XRT possible afterglow
  6. GRB 060218/SN 2006aj: RBO optical observations
  7. GRB 060223B: ART optical limits
  8. GRB 060206: Swift/UVOT Observations
  9. GRB 060209(?): Swift-BAT detection of a possible burst
  10. GRB060206: Swift-BAT detection of a burst
  11. GRB060124: detailed XRT analysis
  12. GRB 060123: Swift detection of a very long, faint burst
  13. GRB 060117: PROMPT Observations
  14. GRB 060116: PROMPT Observations
  15. GRB 060105: Radio observations
  16. GRB 060102 - no XRT afterglow
  17. GRB 051210: Swift/UVOT upper limits
  18. GRB051210: Swift UVOT Observation
  19. GRB 051210: Swift detection of a burst
  20. GRB051111: Swift/UVOT Observations
  21. GRB 051111: Swift-BAT refined analysis
  22. GRB051103: MASTER: OT limit and host galaxy candidates
  23. GRB051028: Swift-XRT refined analysis
  24. GRB051105A: Swift/UVOT Observations
  25. GRB051103:_MASTER_optical_observations
  26. GRB051028: WHT optical candidate
  27. GRB051028: Swift XRT Position
  28. SGR 1806-20: continued moderate activity seen with INTEGRAL
  29. GRB051012: Swift-XRT analysis
  30. GRB 051021B: Refined analysis of the Swift-BAT burst
  31. GRB 051021: SOAR NIR Observations
  32. Swift-BAT triggered on a posible CR Shower or possible GRB
  33. GRB 051012: Swift-BAT detection of burst yesterday
  34. GRB 050922B: optical limit
  35. GRB 050906: Possible X-ray Counterpart
  36. GRB 050906: MARGE Optical Limits
  37. GRB 050824: MDM Observations
  38. GRB050824: First 2 hours of power low optical decay?
  39. GRB050824: MASTER final analysis of the OT observations
  40. GRB050822: Swift/UVOT upper limits
  41. GRB050813: Maidanak I-band observations
  42. GRB 050822: Swift detection of a long burst
  43. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  44. GRB050803: CrAO optical observations, no OT candidate
  45. GRB 050805b: OHP optical limits
  46. GRB 050803: Magellan Observations
  47. GRB 050803: early Swift XRT analysis results
  48. GRB 050730: OHP optical observations
  49. GRB 050802: early Swift XRT analysis results
  50. GRB 050802: Swift/UVOT observations
  51. GRB 050802: XRT position
  52. Swift-BAT trigger 147918 is not a real GRB
  53. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  54. GRB050716, optical observation
  55. GRB 050713, R-band observations at NOT
  56. GRB050607: prompt REM observations
  57. GRB050525: Super-LOTIS observations
  58. GRB 050525: Optical observation
  59. XRF050522: NIR observations of XRT candidate
  60. XRF 050522: Swift XRT refined analysis
  61. GRB050502b: Early Observation
  62. GRB 050505, early TAROT observation
  63. GRB050509a: Swift UVOT observations
  64. GRB 050509a: Swift XRT Position
  65. Swift Detection of the Burst GRB050509
  66. GRB 050505: Keck I-band Magnitude
  67. GRB 050505: early time observations
  68. GRB (?) 050504: IR Observations, Intriguing Source
  69. GRB050326: optical limit
  70. Swift Detection of GRB 050319
  71. RXTE Observations of GRB050318
  72. GRB050309: CONCAM pre-trigger and trigger coincident optical
  73. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  74. GRB 050219b: Swift XRT Position
  75. GRB050215b: Swift UVOT Detection of Afterglow Emission
  76. GRB 050215b: XRT confirmation of IR afterglow candidate
  77. GRB 050215B: candidate afterglow
  78. GRB 050215B: UKIRT K-band imaging
  79. GRB 050215b: Swift XRT Observations
  80. GRB050126: MASTER optical limit for KECK OT
  81. GRB050126: MASTER optical observations
  82. GRB050117: Palomar WIRC Ks-band observations
  83. GRB 041217: Optical observations
  84. GRB041226: ROTSE-III Optical Observations
  85. GRB041218: Continued P60 Optical Observations
  86. GRB 041218: Optical observations
  87. GRB041211,optical observation
  88. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  89. SGR 1806-20 still active
  90. GRB040924,optical observation
  91. IBAS GRB Alerts 1978-1980
  92. GRB040903 - A XRF?
  93. XRF040812: GMRT observations
  94. GRB 040812: Optical counterparts of CXO sources
  95. GRB 040812: Keck and LCO optical observations
  96. GRB 040812: Keck and LCO observations
  97. GRB040624: optical monitoring at TNG
  98. XRF040701: Second-Epoch Chandra Observations
  99. XRF040701: VLA Observations
  100. XRF040701: First-Epoch Chandra Observations

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