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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"

16000 results found.

  1. GRB051117B: optical observation
  2. GRB051111: optical observaion
  3. GRB051117b: No Swift/UVOT Detection
  4. GRB051111: Rc optical observations: correction
  5. GRB051111: Rc optical observations
  6. GRB 051109B: GAO 150cm telescope Optical limit
  7. GRB 051109A : GAO 150cm telescope Rc-band detection
  8. GRB 051021 Optical Observations
  9. GRB 051117B: MARGE Optical Limits
  10. GRB 051117B,optical observation
  11. GRB 051117B: Optical observations
  12. GRB 051117B: ROTSE-III Optical Limits
  13. GRB 051028 Optical Observations
  14. GRB050925: analysis of the XMM-Newton observation
  15. GRB051109A optical observations
  16. GRB 051111: Radio afterglow
  17. GRB 051111: AEOS optical observations
  18. GRB051111: Swift/UVOT Observations
  19. GRB 051111A : R-band temporal decay index based on Lulin
  20. GRB051111: XRT preliminary analysis
  21. GRB 051109A Optical Observations
  22. GRB 051111A : Lulin BVRI multi band afterglow observation
  23. GRB 051111A: KAIT optical observations
  24. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  25. GRB 051109A
  26. GRB 051105a: GETS optical limit
  27. GRB 051109A: KAIT optical observations
  28. Early RAPTOR measurements of GRB 051109a - the movie.
  29. GRB 051109B: ROTSE-III Optical Limits
  30. GRB 051109A: Swift-UVOT Observations
  31. GRB 051109B : Lulin Optical Observations
  32. GRB 051109A : Lulin BVRI Optical afterglow observation
  33. GRB051109A: XRT refined analysis
  34. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  35. GRB 051109B Kiso optical follow-up observation
  36. GRB051105B: REM Optical observation
  37. GRB 051109: HET Optical Spectrum and Absorption Redshift
  38. GRB 051109: Rc and Ic observations
  39. GRB 051109a: IR Photometry and Astrometry
  40. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  41. GRB051105B: Swift/XRT upper limit
  42. GRB051103: optical observations
  43. GRB 051103, optical observations
  44. GRB051103: MASTER: OT limit and host galaxy candidates
  45. GRB051028: Swift-XRT refined analysis
  46. GRB 051105a, observation from Naini Tal and OSN
  47. GRB 051105A, 2nd epoch optical observations
  48. GRB 051105A: TNG optical observations
  49. GRB051105A: Swift/UVOT Observations
  50. GRB 051105A, optical observations
  51. GRB 051105b: ART optical limits
  52. GRB 051105B (INTEGRAL 2701): Optical observation
  53. GRB 051105: Optical limit
  54. GRB 051016B host spectroscopy and redshift
  55. GRB051016B: optical observation
  56. Recent GRB UBVRcIc field photometry
  57. GRB 051022: RTT150 optical observations
  58. GRB 051021A: RTT150 optical observations
  59. GRB051028: optical observations
  60. GRB051028: confirmation of the afterglow
  61. GRB051028: WHT optical candidate
  62. GRB 051028 (=H3951): A GRB localized by HETE
  63. GRB051028:MASTER optical observations
  64. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  65. GRB 051021, Optical Observations
  66. GRB 051022: XRT Refined Spectral and Temporal Analysis
  67. GRB 051022, refined optical astrometry
  68. GRB051021a: optical observations
  69. GRB051021A: Swift XRT refined analysis
  70. GRB051022: Optical Observations
  71. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  72. GRB 051021, SMARTS optical/IR observations
  73. GRB 051022 (=H3950): SXC Flight Localization is Valid
  74. GRB051021: Swift/UVOT Upper Limits
  75. GRB 051022: SSO40 Optical Observations
  76. GRB051022,optical observation
  77. GRB 051022A: ROTSE-III Optical Limits
  78. GRB051022 (=H3590), A GRB Detected By HETE
  79. GRB 051022: Optical observations
  80. GRB 051021,optical observation
  81. GRB051021: Swift XRT analysis
  82. GRB051021 (=H3947): Refined Analysis
  83. GRB 051021 : optical afterglow observation at Lulin
  84. GRB 051021: Optical observations
  85. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  86. GRB 051021: Optical observations and candidate afterglow
  87. GRB051021.6: MASTER optical observation
  88. GRB051021: A GRB Localized by HETE
  89. GRB 050502b: Optical limit
  90. GRB 051016b: Optical limit
  91. GRB 051016b: Gemini Near IR Observations
  92. GRB 051016B: Swift/UVOT detection
  93. GRB 051016B,optical observation
  94. GRB 051016B : Optical follow-up at Lulin
  95. GRB 051016: LCO optical and near-IR imaging
  96. GRB051006: optical observations
  97. GRB050805A: Rc optical observations
  98. GRB051008: optical candidate
  99. GRB051011: MASTER optical observation
  100. GRB051008: optical observation

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