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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. GRB070129: MITSuME optical observation
  2. Radio detection of GRB 070125
  3. GRB061217: MAGIC telescope GeV observation
  4. GRB 070125: confirmation of pseudo-redshift
  5. GRB 070129, Swift-BAT refined analysis of a particularly long
  6. GRB 070129: Xinglong TNT optical Upper Limit
  7. GRB 070129: Swift-XRT Refined Analysis
  8. GRB 070129: VLT observations
  9. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  10. GRB 070129: Swift detection of a burst
  11. GRB 070126: Swift/UVOT refined analysis
  12. GRB 070125: further AAVSO optical observations
  13. GRB 070125: MITSuME Okayama optical observation
  14. Konus-Wind observation of GRB 070125
  15. GRB 070125: AAVSO optical observations
  16. GRB 070125: optical observations
  17. GRB 070126: VLT observations
  18. GRB070126: Swift-XRT possible detection of an afterglow
  19. GRB 070125: PROMPT detections
  20. GRB 070124: Suzaku WAM observation of the prompt emissions
  21. GRB 070125: WSRT Radio Observations
  22. GRB 070125: UVOT Detection in Ultraviolet Filters
  23. GRB 070126, Swift-BAT refined analysis of a very faint burst
  24. GRB070125: Optical observation by Kanata
  25. GRB070124: Swift-XRT Observation
  26. Possible GRB 070126: Swift/UVOT Upper Limit
  27. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  28. GRB 070125: Xinglong TNT optical observations
  29. GRB 070125: Continued P60 Observations
  30. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  31. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  32. GRB 070125: Lick 3m Spectroscopy
  33. GRB070125: Swift-XRT Refined Analysis
  34. GRB 070125: SARA detection in R
  35. GRB 070125: P60 Optical Afterglow Candidate
  36. GRB 070126?: Swift detection of a possible burst
  37. GRB070125 redshift request
  38. RHESSI Spectrum of GRB070125
  39. IPN-BAT localization of GRB070125 (very long duration, intense)
  40. Konus-Wind observation of short hard GRB 070124
  41. IPN localization of GRB070124 (short duration, hard spectrum)
  42. GRB 070110: optical break
  43. Swift-BAT trigger 257213 is a Galactic Center transient
  44. GRB 070110: Continued Detection and Request for Ground Followup
  45. GRB 050904: Second Epoch of HST/NICMOS Observations
  46. GRB 070110: Ep,i - Eiso correlation
  47. GRB 070107: Suzaku WAM observation of the prompt emission
  48. GRB 070110: VLT R-band photometry
  49. GRB 070110 declared a "Burst of Interest" by Swift team
  50. Further Retractions of previous Swift-BAT triggers
  51. Swift-BAT Trigger 255685 is not a GRB
  52. Trigger 255685: Swift detection of a possible burst
  53. GRB 070110: VLT absorption redshift
  54. GRB 070110: UVOT Observations of a Candidate Afterglow
  55. GRB070110: Swift XRT Team refined analysis
  56. GRB 070110, Swift-BAT refined analysis
  57. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  58. GRB 070110: Swift detection of a burst with a possible optical afterglow
  59. IBAS Alert n. 4047: Not a GRB
  60. GRB070107: Swift/XRT refined analysis
  61. GRB 070107: Possible UVOT Afterglow
  62. GRB 070107, Swift-BAT refined analysis
  63. GRB 070107: Swift/XRT position
  64. GRB 070107: Swift detection of a burst
  65. VLA observation of GRB 061222B
  66. VLA detection of GRB 061222A
  67. GRB070103: APO SPIcam i' and z' limits
  68. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  69. GRB070103: KPNO 4m+FLAMINGOS J limit
  70. GRB 070103: Swift/UVOT Upper limits
  71. GRB070103: Swift XRT refined analysis
  72. GRB 070103, Swift-BAT refined analysis
  73. GRB 070103: NOT observations
  74. GRB 070103: TAROT Calern observatory optical observations
  75. GRB 070103: Swift detection of a burst
  76. Retractions of previous Swift-BAT triggers
  77. GRB061222a: optical observations
  78. erratum : SDSS Pre-burst Observations of GRB061126
  79. Konus-Wind observation of GRB 061222A
  80. GRB 061210: Swift/XRT Astrometry Correction
  81. GRB 050826: MDM Redshift
  82. GRB 061222B: TAROT La Silla observatory early optical observations
  83. GRB 061218: TAROT La Silla observatory early optical observations
  84. GRB 061222A: MITSuME Akeno optical upper limits
  85. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  86. GRB 061222B: MITSuME Akeno optical upper limits
  87. GRB 061222A: Xinglong Optical Limit
  88. GRB 061222A: Gemini Afterglow Candidate
  89. GRB 061222B, Swift-BAT refined analysis
  90. GRB061222A Swift/UVOT: Upper Limits
  91. GRB 061222B: Swift/UVOT Upper limits
  92. GRB 061222B: Observation with the KANATA 1.5m telescope
  93. GRB061222B: Swift-XRT Refined Analysis
  94. GRB 061222A: Observation with the KANATA 1.5m telescope
  95. GRB 061222B: BOOTES-IR optical observations
  96. GRB 061222B: SARA upper limit
  97. GRB 061222A: Swift-XRT refined analysis
  98. GRB 061217: Magellan host galaxy redshift
  99. GRB 061222A, Swift-BAT refined analysis
  100. GRB 061222B: REM NIR/optical observations

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