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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"

27558 results found.

  1. GRB 071122: Corrected P60 Coordinates
  2. GRB071122: Gemini Absorption redshift
  3. GRB 071122: P60 Optical Afterglow Candidate
  4. GRB 071122: ROTSE-III Optical Limits
  5. GRB 071122: Swift detection of a burst
  6. GRB 071118: P60 Observations
  7. GRB071118 MITSuME OAO optical observation
  8. GRB 071118: Observations from OSN
  9. GRB 071117: VLT observations and probable redshift
  10. Swift/UVOT observations of GRB071118
  11. GRB 071117: Swift-XRT revised position
  12. Swift XRT follow-up observations of GRB071008
  13. Swift/UVOT upper limits for GRB 071117
  14. GRB071118: Swift XRT refined analysis
  15. GRB 071117: Gemini Optical Afterglow Discovery
  16. GRB 071117: TAROT La Silla observatory optical observations
  17. GRB 071118: Swift detection of a burst
  18. GRB 071117: Gemini Observations
  19. GRB 071117: Las Campanas optical observations
  20. GRB 071117: Swift-XRT refined analysis
  21. VLT FORS2 observations of short hard GRB071112B
  22. GRB 071117: Swift/XRT position
  23. GRB 071117: Initial Swift/UVOT observations
  24. GRB 071117: Swift detection of a bright burst
  25. Swift detection of MXB 0656-072
  26. VLA radio upper limit on GRB 071112C
  27. ATCA radio observations of short hard burst GRB 071112B
  28. Correction to the Swift-BAT Transient Identification (trigger=296683)
  29. GRB 071112C: WSRT Radio Observations
  30. GRB 071112C: optical observation
  31. GRB 071112C: optical observation
  32. GRB 071112C: emission lines and refined VLT redshift
  33. GRB 071112C: SARA upper limit
  34. GRB 071112C : Second Epoch Lulin R-band observations
  35. GRB071112C MITSuME Okayama Optical Observation
  36. GRB 071112C: Swift-BAT refined analysis
  37. GRB 071112C: Swift/UVOT observations
  38. GRB 071112C: Swift XRT refined analysis
  39. GRB 071112C: Optical observations at Crni Vrh
  40. GRB 071112C: VLT redshift
  41. GRB 071112B: Gemini Optical Imaging
  42. GRB 071112B: Swift-XRT preliminary analysis
  43. GRB071112C: NOT observations
  44. GRB 071112C: Palomar Pre-Imaging
  45. GRB 071112C : Lulin R-band observation
  46. Swift XRT follow-up observations of GRB071028B
  47. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  48. GRB 071112C: Optical and NIR afterglows observed with KANATA
  49. GRB 071112C: Swift detection of a burst with an optical counterpart
  50. GRB 071112B: Swift detection of a short hard burst
  51. GRB 071112: Swift detection of a possible burst
  52. GRB071109: Super-LOTIS observations
  53. VLA IInd observation of INTEGRAL burst GRB 071109
  54. Swift/UVOT initial analysis of GRB071109
  55. GRB 071109: further Swift-XRT analysis
  56. No radio detection at Swift-XRT position
  57. GRB 071109: Swift-XRT possible X-ray counterpart
  58. VLA prompt radio detection of the INTEGRAL burst 071109
  59. GRB 071104: Swift-XRT Team Refined Analysis
  60. GRB 071104: Possible Swift UVOT Afterglow Candidate
  61. GRB 071104: Swift-XRT position
  62. GRB071010b: optical observation
  63. Swift XRT and UVOT observations of GRB071028B
  64. GRB 071101: Swift-XRT Team refined analysis
  65. GRB071101: Optical and NIR upper limits by KANATA
  66. GRB0711101: Two new source from Xinglong TNT observation
  67. GRB 071101: TAROT Calern observatory optical observations
  68. GRB 071101: Swift XRT position
  69. GRB 071101: a nearby galaxy
  70. GRB 071101: Swift detection of a burst
  71. GRB 071031: Swift/UVOT detection of afterglow
  72. GRB 071031: Swift-XRT Team refined analysis
  73. GRB 071020: MITSuME Akeno optical observations
  74. GRB 071031: REM NIR and Optical observation
  75. GRB 071031, SMARTS afterglow observations
  76. GRB 071031: VLT high-resolution spectroscopy
  77. GRB071031: Rapid PROMPT Detections
  78. GRB 071031: GROND detection in all bands
  79. GRB 071031: Swift detection of a burst with an optical counterpart
  80. GRB 071028B Swift-BAT detection of a burst
  81. GRB071025: Optical+NIR observations
  82. GRB 071028: SARA observations of variable source
  83. Swift UVOT upper limits to GRB071028
  84. GRB071028: Xinglong EST V-band upper limit
  85. GRB 071028: Swift-XRT Team refined analysis
  86. GRB 071028: Swift detection of a burst
  87. GRB 071025: Kuiper Telescope Optical Observations
  88. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  89. GRB 071018: Revised BAT position
  90. GRB 071025: SARA VRI upper limits
  91. GRB 071025: SQIID JHK photometry
  92. GRB 071025A: Complex Early-Time IR Behavior, Simultaneous with Gamma- and X-rays
  93. Swift UVOT upper limits
  94. GRB071025: Xinglong TNT I-band upper limit
  95. GRB 071025: Swift-XRT Team refined analysis
  96. GRB 071025: Early Super-LOTIS Observations
  97. GRB 071025: R/I-band update
  98. GRB071021 : CFHT Ks-band observation
  99. GRB 071025: ROTSE-III Refined Analysis
  100. GRB 071025: I-detection, R-dropout?

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