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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"

3850 results found.

  1. GRB 170202A : Xinglong TNT optical observation
  2. GRB 170202A: Swift detection of a burst with an optical afterglow
  3. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  4. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  5. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  6. LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
  7. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  8. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  9. LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002
  10. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  11. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  12. LIGO/Virgo G268556: VLA follow-up of ATLAS17aeu
  13. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  14. LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
  15. GRB 161220A: Swift-XRT refined Analysis
  16. GRB 161220A: Swift detection of a burst
  17. GRB 161219B: Swift detection of a burst with an optical afterglow
  18. GRB 161129A: KWFC z-band photometry
  19. GRB 161129A: Mondy optical observations
  20. GRB 161129A: ISON/UAFO optical observations
  21. GRB 161129A: MITSuME Okayama Ks-band Observation
  22. GRB 161129A: MITSuME Okayama Optical Observation
  23. GRB 161129A: Tautenburg Ic-band observations
  24. GRB 161129A: TSHAO optical observations / possible afterglow+host galaxy
  25. GRB 161117A: Swift/UVOT Detection
  26. GRB 161117A: VLT/X-shooter spectroscopy and redshift
  27. GRB 161117A: Swift detection of a burst with an optical counterpart
  28. Fermi GBM trigger 499467682/161029876 is not a GRB
  29. GRB 161014A: Swift detection of a burst
  30. GRB 160925A: Kottamia R-band observation
  31. GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
  32. Konus-Wind observation of GRB 160910A
  33. IceCube HESE 160814: MASTER OT J130845.02-323254.9 as the possible source of the high energy neutrino
  34. Fermi GBM trigger 494508549 / 160902479 is not a GRB
  35. GRB 160829A: Fermi GBM Detection
  36. GRB 160829A: Fermi-LAT detection of a short GRB
  37. GRB 160825A: not localized by Swift
  38. GRB 160821B: Swift-BAT refined analysis
  39. GRB 160821B: Fermi GBM Detection
  40. GRB 160821B: Swift detection of a short burst
  41. GRB 160821A: Swift detection of a bright burst
  42. GRB 160816A: confirmed fading with the LT
  43. GRB 160816A: RATIR Optical and NIR Observations
  44. GRB 160816A: LCOGT-FTN optical candidate
  45. GRB 160816A: Swift-XRT afterglow detection
  46. GRB 160801A: SAO RAS optical observations
  47. GRB 160801A: NOT upper limits
  48. GRB 160801A: Swift-BAT refined analysis
  49. Global MASTER net follow up of IceCube-160731A
  50. GRB 160801A: Enhanced Swift-XRT position
  51. GRB 160801A: Swift detection of a burst
  52. GBM observation of SGR-like burst from the direction of PSR 1119-6127
  53. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  54. GRB 160703, GRB 160705, GRB 160720, SGR1935+2154: First SGRs and GRBs detected by Lomonosov.
  55. GRB 160714A: MASTER early optical observations
  56. GRB 160714A: Optical observations from OSN
  57. GRB 160625B: TSHAO optical observations
  58. GRB 160709A: Global MASTER Net Fermi GBM Alerts observations
  59. SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
  60. GRB 160625B: RTT150 optical observations
  61. Konus-Wind observation of GRB 160703A
  62. GRB 160625B: SAO RAS monitoring
  63. GRB 160629A: Global MASTER Net Prompt OT observations
  64. GRB 160629A: BTA and GTC redshift
  65. GRB 160629A: a long GBB detected by INTEGRAL
  66. Konus-Wind observation of a bright burst from SGR 1935+2154
  67. SGR 1935+2154: AMI 15 GHz upper limits of the magnetar during outburst
  68. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  69. Swift-BAT refined analysis on the bright event from SGR 1935+2154
  70. Trigger 701590: Swift detection of a bright outburst from SGR 1935+2154
  71. GRB 160624A: Prompt enhanced Swift-XRT position
  72. GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103
  73. Trigger 701182: Swift detection of SGR 1935+2154
  74. SGR 1617-5103 (BAT trigger 700791): Enhanced Swift-XRT position.
  75. Swift-BAT refined analysis of the recent outburst from SGR 1617-5103 (a.k.a. 1E 161348-5055 and 2E 1613.5-5053)
  76. Fermi GBM Trigger 160622573 is not a GRB
  77. GRB 160622A: Swift detection of a possible short GRB or a new SGR
  78. More FERMI GBM bursts from the magnetar SGR 1935+2154
  79. SGR 1935+2154: MAXI/GSC detection
  80. Fermi GBM trigger 488128598/160620637 is not a GRB
  81. Fermi GBM trigger 487974449/160618852 is not a GRB
  82. GRB 160521A: 15 GHz detections and upper limit from AMI
  83. Trigger 689956: Swift detection of a source near the Galactic center
  84. Trigger 689353 (possible transient near Sgr A*), Swift-BAT refined analysis
  85. Trigger 689353: Swift detection of a transient near Sgr A*
  86. Fermi GBM trigger 486562774/160602514 is not a GRB
  87. GRB 160601A: GTC observations confirming transient source decay
  88. GRB 160601A: Swift detection of a short hard burst
  89. Another Swift detection of SGR 1935+2154 (trigger #687124)
  90. Swift detection of SGR 1935+2154
  91. Konus-Wind observation of a bright burst from SGR 1935+2154
  92. FERMI GBM bursts from the magnetar SGR 1935+2154
  93. SGR 1935+2154: AbAO optical upper limit
  94. Fermi GBM triggers of SGR 1935+2154
  95. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  96. Fermi GBM trigger 485124591/160516868 is not a GRB
  97. Trigger 686443: Swift detection of SGR 1935+2154
  98. Fermi GBM trigger 484906918/160514349 is not a GRB
  99. FACT follow-up of the IceCube event 160427A
  100. Interplanetary Network Search for IceCube 160427A

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