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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"

8489 results found.

  1. GRB 200803A: Tiled Swift observations
  2. AX J1846.4-0258: Swift-BAT refined analysis
  3. Konus-Wind detection of GRB 200729A
  4. Swift Detection of an SGR-like flare from AX J1846.4-0258
  5. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  6. GRB 200729A: IceCube neutrino search
  7. GRB 200729A: Spitzer archival source detection
  8. GRB 200729A: NOT optical upper limits
  9. GRB 200729A: Swift detection of a burst
  10. GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
  11. GRB 200723A: Swift ToO observations
  12. GRB 200723A: GOTO candidate afterglow and host galaxy
  13. AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
  14. GRB 200716C: Optical observations from HCT
  15. GRB 200522A: HST NIR counterpart confirmation
  16. GRB 200716C: Swift detection of a burst with an optical counterpart
  17. GRB 200715A: Swift ToO observations
  18. GRB 200714E: Swift ToO observations
  19. GRB 200522A: Candidate Optical/nIR Counterpart from Gemini and HST Imaging
  20. GRB 200713A: Swift detection of a burst
  21. GRB 200711A: KAIT Optical Upper Limit
  22. GRB 200711A: Swift detection of a burst
  23. GRB 200709B/HAWC-200907A: Swift-XRT further observations
  24. HAWC-200907A: No Neutrino Counterpart detected with ANTARES
  25. GRB 200709B: Tiled Swift observations
  26. Trigger 980513: Swift detection of SGR Swift J1818.0-1607
  27. Fermi-GBM Sub-Threshold Detection of GRB 200701A
  28. GRB 200630A: Swift detection of a burst
  29. GRB 200623A: Further MMTCam Observations of XRT Source #3
  30. GRB 200623A: LBT optical observations
  31. GRB 200625A: Swift ToO observations
  32. GRB 200623A: Swift/UVOT Upper Limits
  33. GRB 200623A: OAJ deep multi-color imaging, XRT #2 is pre-detected
  34. GRB 200623A: TNG optical observations
  35. GRB 200623A: AbAO afterglow candidate within XRT #2
  36. GRB 200623A: Swift ToO observations
  37. IceCube-200620A: No significant detection in HAWC
  38. IceCube-200620A: Upper limits from a search for additional neutrino events in IceCube
  39. IceCube-200620A: MASTER previous detection of ZTF20abgvabi/AT2020ncr
  40. IceCube-200620A: not observable by Fermi-GBM
  41. IceCube-200620A: One Candidate Counterpart from the Zwicky Transient Facility
  42. IceCube-200620A: No ANTARES neutrino counterpart
  43. IceCube-200620A - IceCube observation of a high-energy neutrino candidate track-like event
  44. LIGO/Virgo MS200618aq: Retraction of a test binary neutron star candidate
  45. LIGO/Virgo MS200619bf: Retraction of a test binary neutron star candidate
  46. LIGO/Virgo MS200618bx: Retraction of a test binary neutron star candidate
  47. LIGO/Virgo MS200618bq: Retraction of a test binary neutron star candidate
  48. IceCube-200530A - SN2020lls likely unrelated
  49. LIGO/Virgo MS200614ct: Identification of a test binary black hole candidate
  50. IceCube-200615A: No significant detection in HAWC
  51. IceCube-200614A: No significant detection in HAWC
  52. IceCube-200615A: Upper limits from a search for additional neutrino events in IceCube
  53. Fermi-LAT Gamma-ray Observations of IceCube-200614A and detection of a new gamma-ray source, Fermi J0202.8+3132
  54. LIGO/Virgo MS200615ce: Identification of a test binary black hole candidate
  55. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  56. IceCube-200615A: Upper limits from Fermi-GBM Observations
  57. IceCube-200614A: Upper limits from a search for additional neutrino events in IceCube
  58. IceCube-200614A: not observable by Fermi-GBM
  59. LIGO/Virgo MS200615h: Retraction of a test binary neutron star candidate
  60. IceCube-200615A: IceCube observation of a high-energy neutrino candidate event
  61. IceCube-200614A - IceCube observation of a high-energy neutrino candidate track-like event
  62. GRB 200613A: Kitab and AbAO optical afterglow observations, host galaxy candidate
  63. GRB 200613A: Candidate afterglow from OAJ
  64. GRB 200613A: Swift ToO observations
  65. GRB 200612A: Swift detection of a burst
  66. IceCube-200530A - SN2020lam classified as SN II without evidence of CSM interaction
  67. GRB 200522A: Further HST F125W Observations
  68. Correction to the GCN 27886: Previous bursts of 1RXS J1708-4009 (Swift trigger 975998)
  69. 1RXS J1708−4009: Swift-BAT refined analysis
  70. Swift detection of an SGR-like burst from 1RXS J1708−4009
  71. IceCube-200530A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube-200530A: not observable by Fermi-GBM
  73. IceCube-200530A: No significant detection in HAWC
  74. IceCube-200530A: Candidate Counterparts from the Zwicky Transient Facility
  75. IceCube-200530A: No ANTARES neutrino counterpart
  76. IceCube-200530A - IceCube observation of a high-energy neutrino candidate event
  77. GRB 200529A: Swift detection of a burst
  78. GRB 200528A: Swift detection of a burst
  79. IceCube-200523A: Upper limits from a search for additional neutrino events in IceCube
  80. GRB 200522A: HST F125W new point source detection
  81. GRB 200522A: Hubble Space Telescope Near-IR F160W Observations
  82. GRB 200524A: Correction to the GCN 27800
  83. GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
  84. GRB 200524A: GROWTH-India confirmation of optical afterglow
  85. GRB 200524A: Swift ToO observations
  86. IceCube-200523A: Upper limits from Fermi-GBM Observations
  87. IceCube-200523A - IceCube observation of a high-energy neutrino candidate event
  88. GRB 200522A: Coincident catalogued galaxy at z~0.4
  89. GRB 200517A: Swift-XRT Confirmation of afterglow
  90. GRB 200519A: R-band follow-up from HCT
  91. GRB 200519A: LCO Optical Afterglow Detection
  92. Fermi GBM Sub-Threshold Detection of GRB 200517A
  93. GRB 200519A: Swift detection of a burst with an optical afterglow
  94. GRB 200517A: Tiled Swift observations
  95. Swift Detection of a burst from SGR Swift J1818.0-1607
  96. GRB 200514B: GROWTH-India follow-up of ZTF20aazpphd (AT2020jww)
  97. IceCube-200512A: Upper limits from a search for additional neutrino events in IceCube
  98. Fermi GBM Sub-Threshold Detection of GRB 200512A
  99. GRB 200512A: Swift detection of a burst
  100. IceCube-200512A: No Candidate Counterparts from the Zwicky Transient Facility

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