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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"

20510 results found.

  1. GRB 110726A: two epochs of SAO RAS optical observations
  2. GRB 110801A: optical observations in CrAO
  3. EVLA observation for Fermi burst GRB 110721A
  4. GRB110731A: MOA optical observations of the steeply fading afterglow
  5. GRB 110801A: SAO RAS optical observations
  6. GRB 110801A: MASTER OT observations
  7. Swift/UVOT observations of GRB110801A
  8. GRB 110801A: Afterglow redshift from 10.4m GTC
  9. GRB 110801A: ROTSE-III Detection of re-brightening from OT
  10. GRB 110731A / EVLA upper limits
  11. GRB 110731A Gemini-N redshift
  12. GRB110731A: Swift/UVOT Observations
  13. GRB 110731A: NOT photometry
  14. GRB 110731A: FTN+FTS afterglow observations
  15. Sw J1644+57 (GRB 110328A): Continued VLBA Observations
  16. GRB 110721A: Swift observations of afterglow candidate
  17. GRB 110726A: EVLA observations
  18. GRB 110726A: IAC80 R-band observations
  19. GRB 110726A: ROTSE-III refined analysis, fast decay in early phase
  20. GRB 110726A: Further Swift/UVOT Observations
  21. GRB 110726A: Swift/UVOT Detection
  22. GRB 110726A: Liverpool Telescope observations
  23. GRB 110726: ROTSE-III Detection of Optical Counterpart
  24. GRB 110721A: Preliminary Swift/UVOT Upper Limits
  25. GRB 110721A: Gemini-South spectroscopy of the potential optical counterpart
  26. GRB 110721A: potential counterpart candidate
  27. GRB 110709B / EVLA detection of radio counterpart
  28. GRB 110719A / SMA 345 GHz upper limits
  29. GRB 110721A: Fermi-LAT detection
  30. Swift/UVOT observations of GRB110719A
  31. GRB 110715A optical observations
  32. GRB 110715A: ATCA detection of the radio counterpart
  33. GRB110715A: GROND Detection of the Optical/NIR Afterglow
  34. GRB 110715A: APEX detection of the submm counterpart
  35. Swift J1822.3-1606
  36. GRB110715A: VLT redshift
  37. Swift J1822.3-1606: Swift-XRT detection of the X-ray counterpart
  38. GRB 110715A: Swift/UVOT Detection
  39. GRB 110709B: Swift/UVOT Observations
  40. GRB 110709A / EVLA upper limits
  41. GRB 110709B: Additional Gemini observations and deep limits on an optical afterglow
  42. GRB 110709B: Submm observations from APEX
  43. GRB 110709A: Swift/UVOT Upper Limits
  44. GRB 110709A: Konkoly observations
  45. GRB 110708A: Konkoly observations
  46. GRB 110709B BAT refined analysis
  47. GRB 110709B: Swift/UVOT Detection of Possible Optical Flaring
  48. GRB 110709B: Gemini-South additional analysis and photometry
  49. GRB 110709B : A possible source in USNO B 1.0
  50. GRB 110709B: GROND Detection of an Afterglow Candidate
  51. GRB 110709B: Gemini-South optical observations
  52. GRB 110709A : Xinglong TNT upper limit
  53. GRB 110709B: Swift detection of renewed activity at T+11 minutes.
  54. GRB 110708A: Swift/UVOT Observations
  55. GRB 110709A: MASTER-NET optical observations
  56. GRB 110708A: Liverpool Telescope observations
  57. GRB 110708A: Lick observations
  58. Swift J185003.2-005627: 1.23m CAHA and BOOTES-3 observations
  59. GRB 110625A: Fermi GBM and LAT observations
  60. GRB 110625A: Swift/UVOT Upper Limits
  61. GRB 110625A: 1.23m CAHA I-band observations
  62. GRB 110625A: GROND detection of a source inside the XRT error circle
  63. GRB 110625A: Konkoly observations
  64. Swift J185003.2-005627: Swift-XRT/UVOT refined analysis
  65. Swift J185003.2-005627: TAROT La Silla observatory optical observations
  66. Swift J185003.2-005627: TAROT Calern observatory optical observations
  67. GRB 110618A: SMARTS optical observations
  68. GRB 110604A: final update on Swift-XRT observations
  69. GRB 110610A: 1.23m CAHA optical observations
  70. GRB 110610A: Swift/UVOT Upper Limits
  71. GRB 110610A: MASTER-NET optical observations
  72. GRB 110530A: optical observations in Mondy observatory
  73. GRB 110530A: optical observations at Mt. Terskol, second epoch
  74. GRB 110530A: Swift/UVOT Detection of a Fading Afterglow
  75. GRB 110530A: Xinglong TNT observation
  76. GRB 110530A: NOT optical observations
  77. GRB 110530A: optical observations at Mt. Terskol
  78. GRB 110530A: Correction to GCN Circ 12050
  79. GRB 110530A: MASTER OT observations
  80. LAT Observations of GRB110529A
  81. Swift J1644+57/GRB 110328A, Additional HST Observations
  82. GRB 110521A: Swift/UVOT Upper Limits
  83. GRB 110520A: NOT optical follow-ups
  84. GRB 110521A - NOT optical observation
  85. GRB 110521A: MASTER synchronous and early optical observations limit
  86. Swift/UVOT observations of GRB110520A
  87. GRB 110520A: IAC80 I-band observations
  88. GRB 110520A: WHT IR observations
  89. GRB 110520A - NOT optical observation
  90. GRB 110520A: Skynet/DAO optical observations
  91. GRB 110520A: Liverpool Telescope Observations
  92. GRB 110520A: TAROT Calern observatory optical observations
  93. GRB 110520A: MASTER-NET optical observations
  94. Radio observations of GRB 110428A with the EVLA
  95. GRB 110503A: TAROT Calern observatory optical observations
  96. GRB 110503A: Jet Break seen from TLS
  97. GRB 110503A optical observations
  98. GRB 110422A: Herschel FIR observation preliminary report
  99. GRB 110503A: R-band Detection
  100. GRB 110503A: Centimeter observation from EVLA

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