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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"
  1. GRB 070129: VLT observations
  2. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  3. GRB 070129: Swift detection of a burst
  4. GRB 070126: Swift/UVOT refined analysis
  5. GRB 070125: further AAVSO optical observations
  6. GRB 070125: MITSuME Okayama optical observation
  7. Konus-Wind observation of GRB 070125
  8. GRB 070125: AAVSO optical observations
  9. GRB 070125: optical observations
  10. GRB 070126: VLT observations
  11. GRB070126: Swift-XRT possible detection of an afterglow
  12. GRB 070125: PROMPT detections
  13. GRB 070124: Suzaku WAM observation of the prompt emissions
  14. GRB 070125: WSRT Radio Observations
  15. GRB 070125: UVOT Detection in Ultraviolet Filters
  16. GRB 070126, Swift-BAT refined analysis of a very faint burst
  17. GRB070125: Optical observation by Kanata
  18. GRB070124: Swift-XRT Observation
  19. Possible GRB 070126: Swift/UVOT Upper Limit
  20. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  21. GRB 070125: Xinglong TNT optical observations
  22. GRB 070125: Continued P60 Observations
  23. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  24. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  25. GRB 070125: Lick 3m Spectroscopy
  26. GRB070125: Swift-XRT Refined Analysis
  27. GRB 070125: SARA detection in R
  28. GRB 070125: P60 Optical Afterglow Candidate
  29. GRB 070126?: Swift detection of a possible burst
  30. GRB070125 redshift request
  31. RHESSI Spectrum of GRB070125
  32. IPN-BAT localization of GRB070125 (very long duration, intense)
  33. Konus-Wind observation of short hard GRB 070124
  34. IPN localization of GRB070124 (short duration, hard spectrum)
  35. GRB 070110: optical break
  36. Swift-BAT trigger 257213 is a Galactic Center transient
  37. GRB 070110: Continued Detection and Request for Ground Followup
  38. GRB 050904: Second Epoch of HST/NICMOS Observations
  39. GRB 070110: Ep,i - Eiso correlation
  40. GRB 070107: Suzaku WAM observation of the prompt emission
  41. GRB 070110: VLT R-band photometry
  42. GRB 070110 declared a "Burst of Interest" by Swift team
  43. Further Retractions of previous Swift-BAT triggers
  44. Swift-BAT Trigger 255685 is not a GRB
  45. Trigger 255685: Swift detection of a possible burst
  46. GRB 070110: VLT absorption redshift
  47. GRB 070110: UVOT Observations of a Candidate Afterglow
  48. GRB070110: Swift XRT Team refined analysis
  49. GRB 070110, Swift-BAT refined analysis
  50. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  51. GRB 070110: Swift detection of a burst with a possible optical afterglow
  52. IBAS Alert n. 4047: Not a GRB
  53. GRB070107: Swift/XRT refined analysis
  54. GRB 070107: Possible UVOT Afterglow
  55. GRB 070107, Swift-BAT refined analysis
  56. GRB 070107: Swift/XRT position
  57. GRB 070107: Swift detection of a burst
  58. VLA observation of GRB 061222B
  59. VLA detection of GRB 061222A
  60. GRB070103: APO SPIcam i' and z' limits
  61. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  62. GRB070103: KPNO 4m+FLAMINGOS J limit
  63. GRB 070103: Swift/UVOT Upper limits
  64. GRB070103: Swift XRT refined analysis
  65. GRB 070103, Swift-BAT refined analysis
  66. GRB 070103: NOT observations
  67. GRB 070103: TAROT Calern observatory optical observations
  68. GRB 070103: Swift detection of a burst
  69. Retractions of previous Swift-BAT triggers
  70. GRB061222a: optical observations
  71. erratum : SDSS Pre-burst Observations of GRB061126
  72. Konus-Wind observation of GRB 061222A
  73. GRB 061210: Swift/XRT Astrometry Correction
  74. GRB 050826: MDM Redshift
  75. GRB 061222B: TAROT La Silla observatory early optical observations
  76. GRB 061218: TAROT La Silla observatory early optical observations
  77. GRB 061222A: MITSuME Akeno optical upper limits
  78. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  79. GRB 061222B: MITSuME Akeno optical upper limits
  80. GRB 061222A: Xinglong Optical Limit
  81. GRB 061222A: Gemini Afterglow Candidate
  82. GRB 061222B, Swift-BAT refined analysis
  83. GRB061222A Swift/UVOT: Upper Limits
  84. GRB 061222B: Swift/UVOT Upper limits
  85. GRB 061222B: Observation with the KANATA 1.5m telescope
  86. GRB061222B: Swift-XRT Refined Analysis
  87. GRB 061222A: Observation with the KANATA 1.5m telescope
  88. GRB 061222B: BOOTES-IR optical observations
  89. GRB 061222B: SARA upper limit
  90. GRB 061222A: Swift-XRT refined analysis
  91. GRB 061217: Magellan host galaxy redshift
  92. GRB 061222A, Swift-BAT refined analysis
  93. GRB 061222B: REM NIR/optical observations
  94. GRB 061222b: Refined redshift
  95. GRB 061222b, SMARTS optical/IR afterglow observations
  96. GRB 061222B: TAROT La Silla observatory afterglow observation
  97. GRB 061222B: TAROT La Silla observatory optical observations
  98. GRB 061222b: Magellan redshift
  99. GRB 061222B: Swift detection of a burst
  100. GRB 061222b: optical afterglow

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