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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"

36077 results found.

  1. GRB 050814: Swift XRT Afterglow Localization
  2. GRB 050814: Swift detection of a burst
  3. GRB 050813: Magellan detection of a high redshift galaxy cluster
  4. GRB050813: RTT150 optical observations
  5. GRB 050813: I-band observations
  6. GRB050813, SDSS pre-burst observations
  7. GRB 050813: KAIT optical limit
  8. GRB 050813: Swift-BAT refined analysis
  9. GRB 050813: Photometry of object in XRT error circle
  10. GRB 050813: Swift XRT afterglow localization
  11. RBO GRB 050714A and GRB 050716 observations
  12. GRB 050813: Possible Short Swift-BAT GRB
  13. Swift-BAT trigger 150131 is not a GRB
  14. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  15. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  16. GRB050803: CrAO optical observations, no OT candidate
  17. GRB 050730: WSRT Radio Observations
  18. GRB 050803: PROMPT BVRcIc Observations
  19. GRB 050807: ROTSE-III Optical Limits
  20. GRB 050730, optical observation
  21. GRB050805b: CrAO optical limit
  22. GRB050805a : Null detection report
  23. GRB050730, optical observations
  24. GRB050803, optical observations
  25. Swift-BAT trigger 149118 is very likely not a GRB
  26. Retraction of Swift Trigger 149131 (GRB 050805B)
  27. GRB 050805b: OHP optical limits
  28. GRB 050805b: TAROT optical limits
  29. GRB050805b: MASTER optical observations
  30. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  31. GRB050805a: MASTER optical candidat
  32. Swift-BAT trigger 149118 is probably not a GRB
  33. GRB 050803: RTT150 optical observations
  34. GRB050803: CrAO optical observations, possible OT candidate
  35. GRB 050803: Keck Observations
  36. GRB 050803: Swift-BAT refined analysis
  37. GRB 050802.422: Fading of the afterglow and detection of the host
  38. GRB050803: MASTER further analys
  39. GRB 050803, optical observations
  40. GRB 050803: Magellan Observations
  41. GRB 050803: early Swift XRT analysis results
  42. GRB 050803: TAROT optical limits
  43. GRB050803: MASTER optical observations
  44. GRB050802: Tentative absorption redshift
  45. GCN GRB observation 050713A
  46. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  47. GRB 050802: Swift/UVOT optical and UV detections
  48. GRB050802: CrAO optical observations
  49. GRB050801: Unchanged decay slope
  50. GRB 050730: OHP optical observations
  51. GRB 050802: early Swift XRT analysis results
  52. GRB 050802: Swift/UVOT observations
  53. GRB 050802 : Lulin Optical follow-up observation
  54. GRB 050802: Swift-BAT refined analysis
  55. GRB050801: Optical photometry and decay index
  56. GRB 050802: XRT position
  57. GRB 050802: Swift Gamma-ray Burst
  58. GRB 050730: Preliminary Analysis of MIKE Spectrum
  59. GCN 050801: early Swift XRT analysis results
  60. GRB 050801: Swift-BAT refined analysis
  61. GRB 050801, SMARTS optical/IR afterglow observations
  62. GRB 050801, afterglow observations
  63. GRB 050730, corrected photometry and break?
  64. GRB 050801: ROTSE-III Early Afterglow Break
  65. GRB050801: Swift-BAT detection of a burst
  66. GRB 050801: ROTSE-III Detection of Possible Counterpart
  67. GRB 050730: XRT refined analysis
  68. Correction to GCN Circ 3476 on GRB050525A
  69. GRB 050730: early TAROT optical observations
  70. GRB 050726: PROMPT Rc Observations
  71. GRB 050730: RTT150 optical observations
  72. GRB 050730, spectra and optical photometry
  73. GRB050730: Refined BAT analysis of the Swift-BAT burst
  74. GRB 050730: Swift XRT afterglow observations
  75. GRB 050730 XMM-Newton observation
  76. GRB 050730: PROMPT VRcIc Observations
  77. GRB050730, afterglow observations
  78. GRB050730: confirmation of redshift
  79. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  80. GRB 050730, SMARTS optical/IR afterglow observations
  81. GRB 050730 : Planned XMM-Newton observation
  82. GRB050730: Liverpool Telescope optical observations
  83. GRB 050730, optical candidate
  84. GRB050730: Swift-BAT detection of a weak burst
  85. GRB 050713A: Swift XRT extended light curve
  86. GRB 050709: PROMPT Rc Observations
  87. GRB050713b: Maidanak optical observations
  88. GRB 050724: Secure Host Redshift from Keck
  89. GRB 050724: WHT optical observations
  90. GRB 050724: Chandra Observations of the X-ray Afterglow
  91. GRB050713: analysis of the XMM-Newton observation
  92. GRB 050724, SMARTS optical/IR afterglow observations
  93. GRB 050726, SMARTS optical/IR observations
  94. Swift-BAT trigger 147918 is not a real GRB
  95. GRB 050727: RTT150 optical observations
  96. GRB050724: VLT observations of the variable source
  97. GRB050727: KAIT optical limit
  98. GRB050709: Second Epoch Chandra Observation
  99. GRB 050726: PROMPT Rc Observations
  100. GRB050709: Second Epoch Chandra Observation

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