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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"

900 results found.

  1. Trigger 933285: Swift detection of the brightest burst so far from SGR 1935+2154
  2. Trigger 933276: Swift detection of further activity from SGR 1935+2154
  3. Fermi GBM GRB 191104C (trigger 594592184 / 191104854) is not a GRB
  4. Fermi GBM GRBs 191104 A, B, C and triggers 594534420/191104185 and 594563923/191104527 are not GRBs
  5. SGR 1935+2154: Swift-BAT refined analysis
  6. GRB 191104B/GRB 191104C are SGR 1935+2154
  7. Trigger 933083: Swift detection of SGR 1935+2154
  8. Fermi GBM triggers 594523229/191104056 and 594528816/191104120 are not GRBs
  9. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  10. IceCube-191001A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  11. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  12. LIGO/Virgo S190930s: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  13. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  14. LIGO/Virgo S190924h: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  15. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  16. IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  17. HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  18. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  19. LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  20. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  21. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  22. LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  23. LIGO/Virgo S190828j: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  24. Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
  25. IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  26. HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation
  27. IceCube 190730A: one weakly associated counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  28. Fermi-LAT Gamma-ray Observations of IceCube-190712A
  29. Fermi-LAT Gamma-ray Observations of IceCube-190504A
  30. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  31. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  32. GRB 190326A: Swift XRT and UVOT follow-up observations
  33. GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR
  34. INTEGRAL observations of the events in the GWTC-1 catalog
  35. GRB 181201A: a long GRB detected by INTEGRAL
  36. GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
  37. GRB 180809A: further Swift/XRT observations
  38. GRB 180701A/MAXI J2119-045: CALET Gamma-Ray Burst Monitor data search
  39. GRB 180728A: VLT/X-shooter redshift of a nearby energetic GRB
  40. Fermi GBM triggers 552488966/180705548 and 552490104/180705561 are not GRBs
  41. GRB 180701A: MAXI/GSC detection
  42. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  43. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  44. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  45. Trigger 780207: Swift triggers again on AXP CXOU J164710.2-455216/PSR J1647-4552
  46. LIGO/Virgo G298048: Chandra X-ray Update on GW170817
  47. LIGO/Virgo G298048: Discovery of X-ray emission from SSS17a in NGC4993
  48. LIGO/Virgo G298936: Astrosat CZTI upper limits
  49. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  50. LIGO/Virgo G298048: Chandra X-ray observations
  51. GRB170730A detecetd by INTEGRAL. Refined analysis
  52. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  53. GRB 170524A: Swift detection of a burst (or possible new SGR)
  54. LIGO/Virgo G275697: DLT40 follow-up observation
  55. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  56. GRB 160821B: Swift-BAT refined analysis
  57. GBM observation of SGR-like burst from the direction of PSR 1119-6127
  58. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  59. GRB 160703, GRB 160705, GRB 160720, SGR1935+2154: First SGRs and GRBs detected by Lomonosov.
  60. SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
  61. Konus-Wind observation of a bright burst from SGR 1935+2154
  62. SGR 1935+2154: AMI 15 GHz upper limits of the magnetar during outburst
  63. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  64. Swift-BAT refined analysis on the bright event from SGR 1935+2154
  65. Trigger 701590: Swift detection of a bright outburst from SGR 1935+2154
  66. GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103
  67. Trigger 701182: Swift detection of SGR 1935+2154
  68. SGR 1617-5103 (BAT trigger 700791): Enhanced Swift-XRT position.
  69. Swift-BAT refined analysis of the recent outburst from SGR 1617-5103 (a.k.a. 1E 161348-5055 and 2E 1613.5-5053)
  70. Fermi GBM Trigger 160622573 is not a GRB
  71. GRB 160622A: Swift detection of a possible short GRB or a new SGR
  72. More FERMI GBM bursts from the magnetar SGR 1935+2154
  73. SGR 1935+2154: MAXI/GSC detection
  74. Fermi GBM trigger 488128598/160620637 is not a GRB
  75. Fermi GBM trigger 487974449/160618852 is not a GRB
  76. Trigger 689353 (possible transient near Sgr A*), Swift-BAT refined analysis
  77. Trigger 689353: Swift detection of a transient near Sgr A*
  78. Fermi GBM trigger 486562774/160602514 is not a GRB
  79. Another Swift detection of SGR 1935+2154 (trigger #687124)
  80. Swift detection of SGR 1935+2154
  81. Konus-Wind observation of a bright burst from SGR 1935+2154
  82. FERMI GBM bursts from the magnetar SGR 1935+2154
  83. SGR 1935+2154: AbAO optical upper limit
  84. Fermi GBM triggers of SGR 1935+2154
  85. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  86. Fermi GBM trigger 485124591/160516868 is not a GRB
  87. Trigger 686443: Swift detection of SGR 1935+2154
  88. Fermi GBM trigger 484906918/160514349 is not a GRB
  89. GRB 160401A: a long GRB detected by INTEGRAL
  90. SGR 0755-2933, Swift-BAT refined analysis
  91. Swift detection of a likely new SGR: SGR 0755-2933
  92. IBAS Alert 7313 is SGR J1935+2154
  93. GRB 151221A: INTEGRAL detection of a short burst or possible SGR
  94. Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600
  95. Swift-BAT probable detection of an outburst from SGR J1819-1600 (AX J1818.8-1559)
  96. LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
  97. GRB 150912A: A long GRB detected by INTEGRAL
  98. SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
  99. Fermi GBM triggers bn150715759 and bn150715817 are not due to GRBs
  100. Trigger 649113: Swift detection of SGR 1E 1841-045

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