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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

14963 results found.

  1. SGR Swift J1818.0-1607: Swift-BAT refined analysis
  2. GRB 200313A: Fermi GBM detection
  3. IPN triangulation of GRB 200311A
  4. GRB 200313B: Fermi GBM Final Real-time Localization
  5. SGR Swift J1818.0-1607: BOOTES-4/MET optical limit
  6. GRB 200313A: Fermi GBM Final Real-time Localization
  7. Swift-BAT trigger 960986: Swift detection of a new SGR Swift J1818.0-1607
  8. GRB 200311A: AstroSat CZTI detection
  9. LIGO/Virgo S200224ca: DESGW Summary of DECam Observations
  10. GRB 200311A: Fermi GBM Final Real-time Localization
  11. GRB 200310A: MAXI/GSC detection
  12. GRB 200306C: Swift/UVOT Detection
  13. GRB 200308A: Fermi GBM Final Real-time Localization
  14. GRB 200306C: Calar Alto 2.2m upper limit
  15. GRB 200307A: Fermi GBM Final Real-time Localization
  16. GRB 200306A: AstroSat CZTI detection
  17. GRB 200306C: KCT upper limit of the optical afterglow
  18. GRB 200306B: Fermi GBM Final Localization Correction
  19. GRB 200306C: OSN 1.5m afterglow detection
  20. GRB 200306C: GOTO upper limits
  21. GRB 200306C: BOOTES-1 detection of the optical afterglow
  22. GRB 200306C: FRAM-ORM afterglow detection
  23. GRB 200306C: Swift detection of a burst with an optical counterpart
  24. Swift GRB200306.95: Global MASTER-Net OT detection
  25. Swift GRB200306.95: Global MASTER-Net OT detection
  26. GRB 200306B: Fermi GBM Final Real-time Localization
  27. GRB 200306A: Potential LCO Optical Afterglow Detection
  28. GRB 200306A: Swift detection of a burst
  29. Konus-Wind observation of GRB200303A
  30. GRB200210A AstroSat observations
  31. LIGO/Virgo S200302c: Upper limits from Insight-HXMT/HE observations
  32. GRB 200219A: AstroSat CZTI detection
  33. GRB 200303A: GOTO observations upper limit
  34. GRB 200228A: AstroSat CZTI detection
  35. GRB 200303A: CALET Gamma-Ray Burst Monitor detection
  36. GRB 200219C: VLA Detection
  37. GRB 200303A: Swift detection of a burst
  38. GRB 200303A: Fermi GBM Final Real-time Localization
  39. LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations
  40. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  41. LIGO/Virgo S200302c: No counterpart candidates in HAWC observations
  42. LIGO/Virgo S200302c: Upper limits from Fermi-GBM Observations
  43. GRB 200228B: Liverpool Telescope imaging
  44. GRB 200228C: Insight-HXMT/HE detection
  45. GRB 200228A: Swift/BAT detection and arcminute localization from GUANO
  46. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  47. GRB 200227A: Mondy optical upper limit
  48. GRB 200228B: Swift detection of a burst
  49. GRB 200228B: Fermi GBM Final Real-time Localization
  50. GRB 200227A: Insight-HXMT/HE detection
  51. IceCube-200227A : Upper limits from Insight-HXMT/HE observations
  52. GRB 200228A: Fermi GBM Final Real-time Localization
  53. HAWC-200216A: No Neutrino Counterpart in ANTARES Search
  54. IceCube-200227A: IceCube observation of a high-energy neutrino candidate event
  55. GRB 200227A: Swift detection of a burst
  56. GRB 200227A: Fermi GBM Final Real-time Localization
  57. Konus-Wind observation of GRB 200219C
  58. LIGO/Virgo S200224ca: DESGW Optical counterpart candidates from DECam
  59. Konus-Wind observation of GRB 200219A
  60. GRB 200224A: Calar Alto 2.2m optical afterglow detection
  61. LIGO/Virgo S200225q: Upper limits from Insight-HXMT/HE observations
  62. LIGO/Virgo S200224ca: Upper limits from Insight-HXMT/HE observations
  63. LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
  64. IPN triangulation of GRB 200221A (short)
  65. LIGO/Virgo S200225q: Upper limits from Fermi-GBM Observations
  66. LIGO/Virgo S200224ca: Subaru/Hyper Suprime-Cam follow-up observations
  67. LIGO/Virgo S200225q: No counterpart candidates in HAWC observations
  68. GRB 200224A: Swift/UVOT Detection
  69. GRB 200224C: Fermi GBM Final Real-time Localization
  70. GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
  71. GRB 200224B: Fermi GBM Final Real-time Localization
  72. GRB 200224A: Swift detection of a burst
  73. GRB 200223A: Fermi GBM Final Real-time Localization
  74. IPN triangulation of GRB 200219B (inconsistent with the LIGO/Virgo S200219ac)
  75. GRB 200219C: CALET Gamma-Ray Burst Monitor detection
  76. GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
  77. GRB 200221A: Fermi GBM Final Real-time Localization
  78. GRB 200219C: Swift-XRT afterglow detection
  79. GRB 200219C: Fermi GBM detection
  80. LIGO/Virgo S200213t: AT2020clw/ZTF20aanaoyz, AT2020crd/ZTF20aanakge and AT2020cly/ZTF20aanakes 10.4m GTC spectroscopy
  81. GRB 200219C: Fermi-LAT detection
  82. GRB 200219C: Fermi GBM Final Real-time Localization
  83. LIGO/Virgo S200219ac: Fermi GBM transient event not confidently associated with GW signal
  84. LIGO/Virgo S200219ac: No counterpart candidates in HAWC observations
  85. GRB 200219B: Fermi GBM Final Real-time Localization
  86. GRB 200219A: Swift detection of a short burst
  87. GRB 200219A: Fermi GBM Final Real-time Localization
  88. LIGO/Virgo (S200213t/IceCube neutrino candidate: No counterpart candidates in the Swift-XRT Observations
  89. LIGO/Virgo S200213t: No EM counterparts found from continued GECKO observation of host galaxy candidates
  90. LIGO/Virgo S200213t: APO Upper Limits for ZTF20aanakes/AT2020cly
  91. Further Swift-XRT observations of Swift J0840.7-3516
  92. GRB 200215A: CALET Gamma-Ray Burst Monitor detection
  93. GRB 200216A: Fermi GBM detection
  94. GRB 200216A: Swift/BAT detection and arcminute localization from GUANO
  95. GRB 200216B: Swift detection of a burst
  96. GRB 200216B: Fermi GBM Final Real-time Localization
  97. GRB 200216A: Fermi GBM Final Real-time Localization
  98. LIGO/Virgo S200213t: CLU/NED Galaxies in the 4-Update Localization Volume
  99. GRB 200215A: Fermi GBM detection
  100. GRB 200215A: Swift detection of a burst

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