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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"

20963 results found.

  1. GRB 110928A: Further PAIRITEL NIR Observations
  2. GRB 110928A: Swift-XRT observations
  3. GRB 110928A: PAIRITEL NIR Observations
  4. Swift-BAT trigger 503926 is noise
  5. GRB 110921A: Swift/UVOT Observations
  6. GRB110918A: Lick Observations
  7. GRB 110921A: NOT observations
  8. GRB 110918A: Liverpool Telescope optical observations
  9. GRB 110918A: submm observations from APEX
  10. GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
  11. GRB 110921A : TNT optical counterpart candidate
  12. GRB 110921A: MASTER-Net early limit
  13. GRB 110915B : X-ray afterglow confirmation
  14. GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
  15. GRB 110918A optical observation
  16. GRB 110918A: Gemini-N redshift
  17. GRB 110918A: GROND detection of the afterglow candidate
  18. GRB 110918A: Swift-XRT observations
  19. Konus-Wind observation of GRB 110918A
  20. GRB110918A: BOOTES-1 optical limit
  21. GRB 110915B: GROND Observations of the Optical/NIR Afterglow Candidate
  22. GRB 110915A: Swift/UVOT Upper Limits
  23. GRB 110915B: Swift/UVOT Upper Limits
  24. GRB 110915A: GROND Upper limits
  25. GRB 110915A: Deep Near-IR Limits from Magellan
  26. GRB110915A MITSuME Okayama J-band upper-limit
  27. GRB 110915A: NOT observations
  28. GRB 110915A: 1.23m CAHA I-band observations
  29. GRB 110915A: GMG optical upper limit
  30. GRB 110825A: Further Swift/XRT Observations
  31. GRB 110731A: SAO RAS and Terskol observations
  32. GRB 110906A(?): Burst detection (unconfirmed) from Swift-BAT slew data
  33. GRB 110905A / X-ray transient MAXI J1836-194: TNT optical observation
  34. GRB 110905A: Potential BAT trigger on MAXI J1836-194
  35. GRB 110905A: KAIT observations
  36. GRB 110903A: Swift/UVOT Upper Limits
  37. GRB 110903A: Swift-XRT observations
  38. GRB 110825A: GMG optical observation
  39. GRB110825A: Swift target of opportunity observation
  40. Swift-BAT refined analysis of SFXT IGR J08408-4503 (trigger 501368)
  41. GRB 110820A: MASTER-NET first hour observations
  42. GRB 110820A: Swift/UVOT Upper Limits
  43. GRB 110820A: CQUEAN izY Observation
  44. GRB 110820A: MASTER-NET observations
  45. GRB 110818A: Swift/UVOT Upper Limits
  46. GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
  47. GRB 110801A: optical observations at Mt. Terskol observatory
  48. SGR 1834.9-0846/ GRB 110807A, I-band observations
  49. A new photometric resource for GRB observers
  50. SGR 1834.9-0846/ GRB 110807A: archival IR observations
  51. GRB 110808A: Swift/UVOT Detection
  52. Fermi GBM detection of a SGR-like burst
  53. GRB 110807A: SAO RAS observations
  54. GRB 110726A: two epochs of SAO RAS optical observations
  55. GRB 110801A: optical observations in CrAO
  56. EVLA observation for Fermi burst GRB 110721A
  57. GRB110731A: MOA optical observations of the steeply fading afterglow
  58. GRB 110801A: SAO RAS optical observations
  59. GRB 110801A: MASTER OT observations
  60. Swift/UVOT observations of GRB110801A
  61. GRB 110801A: Afterglow redshift from 10.4m GTC
  62. GRB 110801A: ROTSE-III Detection of re-brightening from OT
  63. GRB 110731A / EVLA upper limits
  64. GRB 110731A Gemini-N redshift
  65. GRB110731A: Swift/UVOT Observations
  66. GRB 110731A: NOT photometry
  67. GRB 110731A: FTN+FTS afterglow observations
  68. Sw J1644+57 (GRB 110328A): Continued VLBA Observations
  69. GRB 110721A: Swift observations of afterglow candidate
  70. GRB 110726A: EVLA observations
  71. GRB 110726A: IAC80 R-band observations
  72. GRB 110726A: ROTSE-III refined analysis, fast decay in early phase
  73. GRB 110726A: Further Swift/UVOT Observations
  74. GRB 110726A: Swift/UVOT Detection
  75. GRB 110726A: Liverpool Telescope observations
  76. GRB 110726: ROTSE-III Detection of Optical Counterpart
  77. GRB 110721A: Preliminary Swift/UVOT Upper Limits
  78. GRB 110721A: Gemini-South spectroscopy of the potential optical counterpart
  79. GRB 110721A: potential counterpart candidate
  80. GRB 110709B / EVLA detection of radio counterpart
  81. GRB 110719A / SMA 345 GHz upper limits
  82. GRB 110721A: Fermi-LAT detection
  83. Swift/UVOT observations of GRB110719A
  84. GRB 110715A optical observations
  85. GRB 110715A: ATCA detection of the radio counterpart
  86. GRB110715A: GROND Detection of the Optical/NIR Afterglow
  87. GRB 110715A: APEX detection of the submm counterpart
  88. Swift J1822.3-1606
  89. GRB110715A: VLT redshift
  90. Swift J1822.3-1606: Swift-XRT detection of the X-ray counterpart
  91. GRB 110715A: Swift/UVOT Detection
  92. GRB 110709B: Swift/UVOT Observations
  93. GRB 110709A / EVLA upper limits
  94. GRB 110709B: Additional Gemini observations and deep limits on an optical afterglow
  95. GRB 110709B: Submm observations from APEX
  96. GRB 110709A: Swift/UVOT Upper Limits
  97. GRB 110709A: Konkoly observations
  98. GRB 110708A: Konkoly observations
  99. GRB 110709B BAT refined analysis
  100. GRB 110709B: Swift/UVOT Detection of Possible Optical Flaring

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