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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"

16157 results found.

  1. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  2. GRB 051221: Discovery of fading optical afterglow
  3. GRB 051221: Possible nearby cluster
  4. GRB 051221: IR Observations at GRB+1hr
  5. GRB051211A (=H3979): Refined Analysis
  6. GRB 051211B: optical afterglow
  7. GRB051211A: possible optical candidate
  8. GRB051105: optical observations
  9. GRB 051211B, optical observation
  10. GRB 051211a: RTT150 optical observations
  11. GRB051211B, RBO optical observations
  12. GRB 051211A: Swift/UVOT upper limits
  13. GRB 051211A,optical observation
  14. GRB 051211B: Swift XRT confirmation of the afterglow
  15. GRB051211B: Liverpool Telescope observation
  16. GRB 051211b: RTT150 optical observations
  17. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  18. GRB 051211B: Swift XRT Observations
  19. GRB 051211: TAROT optical limits
  20. GRB 051211B: a possible optical detection by TAROT
  21. GRB 051211:IAC80 optical observations
  22. HETE SXC localization of GRB 051211 (=H3979)
  23. GRB 051210: Optical imaging from Las Campanas
  24. GRB051210: Swift UVOT Observation
  25. GRB051117B: optical observation
  26. GRB051111: optical observaion
  27. GRB051117b: No Swift/UVOT Detection
  28. GRB051111: Rc optical observations: correction
  29. GRB051111: Rc optical observations
  30. GRB 051109B: GAO 150cm telescope Optical limit
  31. GRB 051109A : GAO 150cm telescope Rc-band detection
  32. GRB 051021 Optical Observations
  33. GRB 051117B: MARGE Optical Limits
  34. GRB 051117B,optical observation
  35. GRB 051117B: Optical observations
  36. GRB 051117B: ROTSE-III Optical Limits
  37. GRB 051028 Optical Observations
  38. GRB050925: analysis of the XMM-Newton observation
  39. GRB051109A optical observations
  40. GRB 051111: Radio afterglow
  41. GRB 051111: AEOS optical observations
  42. GRB051111: Swift/UVOT Observations
  43. GRB 051111A : R-band temporal decay index based on Lulin
  44. GRB051111: XRT preliminary analysis
  45. GRB 051109A Optical Observations
  46. GRB 051111A : Lulin BVRI multi band afterglow observation
  47. GRB 051111A: KAIT optical observations
  48. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  49. GRB 051109A
  50. GRB 051105a: GETS optical limit
  51. GRB 051109A: KAIT optical observations
  52. Early RAPTOR measurements of GRB 051109a - the movie.
  53. GRB 051109B: ROTSE-III Optical Limits
  54. GRB 051109A: Swift-UVOT Observations
  55. GRB 051109B : Lulin Optical Observations
  56. GRB 051109A : Lulin BVRI Optical afterglow observation
  57. GRB051109A: XRT refined analysis
  58. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  59. GRB 051109B Kiso optical follow-up observation
  60. GRB051105B: REM Optical observation
  61. GRB 051109: HET Optical Spectrum and Absorption Redshift
  62. GRB 051109: Rc and Ic observations
  63. GRB 051109a: IR Photometry and Astrometry
  64. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  65. GRB051105B: Swift/XRT upper limit
  66. GRB051103: optical observations
  67. GRB 051103, optical observations
  68. GRB051103: MASTER: OT limit and host galaxy candidates
  69. GRB051028: Swift-XRT refined analysis
  70. GRB 051105a, observation from Naini Tal and OSN
  71. GRB 051105A, 2nd epoch optical observations
  72. GRB 051105A: TNG optical observations
  73. GRB051105A: Swift/UVOT Observations
  74. GRB 051105A, optical observations
  75. GRB 051105b: ART optical limits
  76. GRB 051105B (INTEGRAL 2701): Optical observation
  77. GRB 051105: Optical limit
  78. GRB 051016B host spectroscopy and redshift
  79. GRB051016B: optical observation
  80. Recent GRB UBVRcIc field photometry
  81. GRB 051022: RTT150 optical observations
  82. GRB 051021A: RTT150 optical observations
  83. GRB051028: optical observations
  84. GRB051028: confirmation of the afterglow
  85. GRB051028: WHT optical candidate
  86. GRB 051028 (=H3951): A GRB localized by HETE
  87. GRB051028:MASTER optical observations
  88. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  89. SGR 1806-20: continued moderate activity seen with INTEGRAL
  90. GRB 051021, Optical Observations
  91. GRB 051022: XRT Refined Spectral and Temporal Analysis
  92. GRB 051022, refined optical astrometry
  93. GRB051021B: Swift XRT refined analysis
  94. GRB051021a: optical observations
  95. GRB051021A: Swift XRT refined analysis
  96. GRB051022: Optical Observations
  97. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  98. GRB 051021, SMARTS optical/IR observations
  99. GRB 051022 (=H3950): SXC Flight Localization is Valid
  100. GRB051021: Swift/UVOT Upper Limits

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