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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"

36180 results found.

  1. GRB 050813: Radio Observations
  2. GRB050815: Refined analysis of the Swift-BAT burst
  3. GRB 050815: ROTSE-III Optical Limits
  4. GRB050815: Swift XRT afterglow localization
  5. GRB 050730: Third Epoch WSRT Radio Observations
  6. GRB050814: Fading red source
  7. GRB 050813: Gemini Spectra Revisited
  8. GRB 050813: Non-fading of afterglow candidate
  9. GRB 050814: XRT refined analysis
  10. GRB050814: Refined analysis of the Swift-BAT burst
  11. GRB050813: Gemini Imaging
  12. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  13. GRB 050814: Swift XRT Afterglow Localization
  14. GRB 050814: Swift detection of a burst
  15. GRB 050813: Magellan detection of a high redshift galaxy cluster
  16. GRB050813: RTT150 optical observations
  17. GRB 050813: I-band observations
  18. GRB050813, SDSS pre-burst observations
  19. GRB 050813: KAIT optical limit
  20. GRB 050813: Swift-BAT refined analysis
  21. GRB 050813: Photometry of object in XRT error circle
  22. GRB 050813: Swift XRT afterglow localization
  23. RBO GRB 050714A and GRB 050716 observations
  24. GRB 050813: Possible Short Swift-BAT GRB
  25. Swift-BAT trigger 150131 is not a GRB
  26. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  27. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  28. GRB050803: CrAO optical observations, no OT candidate
  29. GRB 050730: WSRT Radio Observations
  30. GRB 050803: PROMPT BVRcIc Observations
  31. GRB 050807: ROTSE-III Optical Limits
  32. GRB 050730, optical observation
  33. GRB050805b: CrAO optical limit
  34. GRB050805a : Null detection report
  35. GRB050730, optical observations
  36. GRB050803, optical observations
  37. Swift-BAT trigger 149118 is very likely not a GRB
  38. Retraction of Swift Trigger 149131 (GRB 050805B)
  39. GRB 050805b: OHP optical limits
  40. GRB 050805b: TAROT optical limits
  41. GRB050805b: MASTER optical observations
  42. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  43. GRB050805a: MASTER optical candidat
  44. Swift-BAT trigger 149118 is probably not a GRB
  45. GRB 050803: RTT150 optical observations
  46. GRB050803: CrAO optical observations, possible OT candidate
  47. GRB 050803: Keck Observations
  48. GRB 050803: Swift-BAT refined analysis
  49. GRB 050802.422: Fading of the afterglow and detection of the host
  50. GRB050803: MASTER further analys
  51. GRB 050803, optical observations
  52. GRB 050803: Magellan Observations
  53. GRB 050803: early Swift XRT analysis results
  54. GRB 050803: TAROT optical limits
  55. GRB050803: MASTER optical observations
  56. GRB050802: Tentative absorption redshift
  57. GCN GRB observation 050713A
  58. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  59. GRB 050802: Swift/UVOT optical and UV detections
  60. GRB050802: CrAO optical observations
  61. GRB050801: Unchanged decay slope
  62. GRB 050730: OHP optical observations
  63. GRB 050802: early Swift XRT analysis results
  64. GRB 050802: Swift/UVOT observations
  65. GRB 050802 : Lulin Optical follow-up observation
  66. GRB 050802: Swift-BAT refined analysis
  67. GRB050801: Optical photometry and decay index
  68. GRB 050802: XRT position
  69. GRB 050802: Swift Gamma-ray Burst
  70. GRB 050730: Preliminary Analysis of MIKE Spectrum
  71. GCN 050801: early Swift XRT analysis results
  72. GRB 050801: Swift-BAT refined analysis
  73. GRB 050801, SMARTS optical/IR afterglow observations
  74. GRB 050801, afterglow observations
  75. GRB 050730, corrected photometry and break?
  76. GRB 050801: ROTSE-III Early Afterglow Break
  77. GRB050801: Swift-BAT detection of a burst
  78. GRB 050801: ROTSE-III Detection of Possible Counterpart
  79. GRB 050730: XRT refined analysis
  80. Correction to GCN Circ 3476 on GRB050525A
  81. GRB 050730: early TAROT optical observations
  82. GRB 050726: PROMPT Rc Observations
  83. GRB 050730: RTT150 optical observations
  84. GRB 050730, spectra and optical photometry
  85. GRB050730: Refined BAT analysis of the Swift-BAT burst
  86. GRB 050730: Swift XRT afterglow observations
  87. GRB 050730 XMM-Newton observation
  88. GRB 050730: PROMPT VRcIc Observations
  89. GRB050730, afterglow observations
  90. GRB050730: confirmation of redshift
  91. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  92. GRB 050730, SMARTS optical/IR afterglow observations
  93. GRB 050730 : Planned XMM-Newton observation
  94. GRB050730: Liverpool Telescope optical observations
  95. GRB 050730, optical candidate
  96. GRB050730: Swift-BAT detection of a weak burst
  97. GRB 050713A: Swift XRT extended light curve
  98. GRB 050709: PROMPT Rc Observations
  99. GRB050713b: Maidanak optical observations
  100. GRB 050724: Secure Host Redshift from Keck

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