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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"

45770 results found.

  1. GRB 241002B: PRIME near-infrared detection
  2. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  3. GRB 241002C: Swift ToO observations
  4. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  5. IPN triangulation of GRB 240930B / EP 240930a
  6. GRB 241001A : SVOM/VT optical detection
  7. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  8. GRB 241002D: SVOM/GRM observation
  9. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  10. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  11. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  12. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  13. GRB 241002C : MITSuME Akeno optical upper limits
  14. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  15. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  16. GRB241001A: REM optical/NIR upper limits
  17. LIGO/Virgo/KAGRA S241002e: Updated Sky localization
  18. GRB 241002A: Swift/UVOT Upper Limits
  19. EP240930a: Liverpool Telescope observations
  20. GRB 241002A: Swift-XRT refined Analysis
  21. GRB 241002A: LCOGT Optical Upper Limits
  22. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  23. GRB 241001A: Swift/UVOT Detection
  24. GRB 241001A: VLT/X-shooter redshift
  25. GRB 241002B: GOTO optical counterpart candidate
  26. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  27. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  28. GRB 241001A: correction to GCN 37667
  29. Fermi GRB 241002B: Global MASTER-Net observations report
  30. GRB 241001A: Swift-XRT observations
  31. EP trigger ID 01709064214: the X-ray transient is most likely a stellar flare event
  32. GRB 241002B: Fermi GBM Final Real-time Localization
  33. GRB241001A: optical afterglow candidate
  34. GRB 241002A: 1.5m OSN optical upper limit
  35. GRB 241002A: Enhanced Swift-XRT position
  36. GRB 241001A: BOOTES-6/DPRT optical upper limit
  37. LIGO/Virgo/KAGRA S241002e: Identification of a GW compact binary merger candidate
  38. GRB 241002A: Swift detection of a burst
  39. LIGO/Virgo/KAGRA S240930du: Updated Sky localization
  40. GRB 240930B: Fermi GBM Observation
  41. GRB 241001A: Swift ToO observations
  42. GRB 240930B: GRBAlpha detection
  43. GRB 240929A: GRBAlpha detection
  44. EP240930a : KAIT optical upper limit
  45. GRB 241001A : Detection of a soft transient by ECLAIRs onboard SVOM
  46. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  47. EP240930a: EP-FXT follow-up observation update
  48. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  49. EP240930a: GOTO optical upper limits
  50. GRB 240929A: SVOM/GRM observation
  51. EP EP240930a: Global MASTER-Net observations report
  52. EP240930a: EP-WXT detection of a fast X-ray transient
  53. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  54. LIGO/Virgo/KAGRA S240930du: Identification of a GW compact binary merger candidate
  55. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  56. LIGO/Virgo/KAGRA S240930df: 1 counterpart neutrino candidate event from an IceCube neutrino search
  57. AMON NuEM 240926A: Swift XRT Follow-up
  58. GRB 240929A : Leavitt Observatory optical upper limit
  59. Fermi GRB 240930B: Global MASTER-Net observations report
  60. GRB 240930B: Fermi GBM Final Real-time Localization
  61. IPN triangulation of GRB 240926A
  62. GRB 240825A: LBT optical observations
  63. GRB 240928A: SVOM/GRM observation
  64. Fermi GRB 240930A: Global MASTER-Net observations report
  65. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  66. LIGO/Virgo/KAGRA S240930aa: Identification of a GW compact binary merger candidate
  67. GRB 240930A: Fermi GBM Final Real-time Localization
  68. Fermi trigger No 749339671: Global MASTER-Net observations report
  69. Fermi Gamma-ray Burst Monitor trigger 749339671/240929913 is not a GRB
  70. GRB 240929A long GRB detected by INTEGRAL
  71. GRB 240929A: BALROG localization (Fermi Trigger 749332209 / GRB 240929826)
  72. Fermi GRB 240929A: Global MASTER-Net observations report
  73. GRB 240929A: Fermi GBM Final Real-time Localization
  74. Integral GRB240929.83: Global MASTER-Net observations report
  75. IceCube-240929A - IceCube observation of a high-energy neutrino candidate track-like event
  76. Konus-Wind detection of GRB 240912A
  77. Swift Trigger 1256950 is probably not a GRB
  78. Fermi Gamma-ray Burst Monitor trigger 749191601/240928199 is not a GRB
  79. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  80. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  81. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  82. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  83. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  84. GRB 240926A: SVOM/GRM observation
  85. EP trigger ID 01709061302: the X-ray transient is likely a stellar flare event
  86. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240926A
  87. Konus-Wind detection of GRB 240905B
  88. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  89. GW S240915b and S240919bn : Swift UVOT follow-up
  90. EP240919a / GRB 240919A: SVOM/VT upper limit
  91. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  92. EP240918b and EP240918c: EP-FXT follow-up observations
  93. LIGO/Virgo/KAGRA S240925n: Updated Sky localization and Source Classification
  94. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  95. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  96. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  97. Konus-Wind detection of GRB 240918B
  98. IPN triangulation of GRB 240918B
  99. GRB 240905B: VZLUSAT-2 detection
  100. LIGO/Virgo/KAGRA S240922df: Updated Sky localization

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