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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"

28304 results found.

  1. GRB 240727A: VIRT Optical Upper Limit
  2. GRB 241018A: X-ray afterglow candidate observed by MXT
  3. GRB 241017A: Swift-XRT observations
  4. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  5. GRB 241001A: EP-FXT afterglow detection
  6. GRB 241017A: GROWTH-India Telescope optical upper limit
  7. GRB241017A: TOO Observations by SVOM/MXT
  8. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  9. GRB 241017A: J-band upper limit from WINTER
  10. GRB 241016B: SVOM/GRM observation
  11. GRB 241017A : Detection of a weak and soft long duration GRB by SVOM/ECLAIRs
  12. GRB 241010A: Swift-BAT refined analysis
  13. GRB 241013B: Fermi GBM Observation
  14. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  15. GRB 241013A: Fermi GBM Observation
  16. GRB 240916A: radio detection with the VLA
  17. GRB241013A: REM observations
  18. GRB 241009A: LCO optical upper limits
  19. Integral GRB241013.04: Global MASTER-Net observations report
  20. LIGO/Virgo/KAGRA S241009em: Updated Sky localization
  21. LIGO/Virgo/KAGRA S241011k: Updated Sky localization
  22. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  23. LIGO/Virgo/KAGRA S241011k: Identification of a GW compact binary merger candidate
  24. GRB 241009A: GRANDMA optical upper limits
  25. GRB 241009A: Swift-XRT afterglow detection
  26. GRB 241010A: JinShan optical observations and potential host galaxy
  27. GRB 241010A: Swift-XRT refined Analysis
  28. LIGO/Virgo/KAGRA S241007bw: Updated Sky localization
  29. Fermi trigger No 750211959: Global MASTER-Net observations report
  30. Fermi trigger No 750291012: Global MASTER-Net observations report
  31. GRB 241010A: J-band observations with WINTER
  32. LIGO/Virgo/KAGRA S241009an: Updated Sky localization
  33. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  34. GRB 241010A: Enhanced Swift-XRT position
  35. GRB 241010A: LCO optical observations
  36. GRB 241010A: Swift detection of a burst with an optical counterpart
  37. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  38. GRB 241006A: Swift-BAT refined analysis
  39. LIGO/Virgo/KAGRA S241009l: Updated Sky localization
  40. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  41. GRB 241008A: Fermi GBM Observation
  42. GRB 241002B: Swift-XRT afterglow detection
  43. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  44. GRB 241002A: NOT optical upper limits
  45. LIGO/Virgo/KAGRA S241009l: Identification of a GW compact binary merger candidate
  46. GRB 241008A: BALROG localization (Fermi Trigger 750117609 / GRB 241008917)
  47. IceCube-241006A: No candidates from the Zwicky Transient Facility
  48. GRB 241006A: GRANDMA optical upper limits
  49. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  50. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  51. GRB 240910A: LBT optical observations
  52. GRB 241006A: Swift-XRT refined Analysis
  53. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  54. GRB 241006A: PRIME near-infrared upper limits
  55. GRB 241006A: Swift/UVOT Upper Limits
  56. LIGO/Virgo/KAGRA S241007bw: Identification of a GW compact binary merger candidate
  57. GRB 241001A: Swift-XRT afterglow detection
  58. GRB 241006A: Enhanced Swift-XRT position
  59. GRB 241006A: Swift detection of a burst
  60. GRB 240930B: SVOM/C-GFT optical upper limit
  61. LIGO/Virgo/KAGRA S241006k: Identification of a GW compact binary merger candidate
  62. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  63. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  64. GRB 241002B: Fermi GBM Observation
  65. GRB 241002B: Swift-XRT observations
  66. GRB 241002C: SVOM/C-GFT optical upper limit
  67. GRB 241002A: Swift-BAT refined analysis
  68. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  69. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  70. GRB 241002B: PRIME near-infrared detection
  71. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  72. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  73. IPN triangulation of GRB 240930B / EP 240930a
  74. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  75. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  76. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  77. GRB 241002C : MITSuME Akeno optical upper limits
  78. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  79. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  80. GRB241001A: REM optical/NIR upper limits
  81. LIGO/Virgo/KAGRA S241002e: Updated Sky localization
  82. GRB 241002A: Swift/UVOT Upper Limits
  83. EP240930a: Liverpool Telescope observations
  84. GRB 241002A: Swift-XRT refined Analysis
  85. GRB 241002A: LCOGT Optical Upper Limits
  86. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  87. GRB 241001A: Swift/UVOT Detection
  88. GRB 240929A: Liverpool Telescope prompt followup observations
  89. GRB 241001A: Swift-XRT observations
  90. GRB241001A: optical afterglow candidate
  91. GRB 241002A: Enhanced Swift-XRT position
  92. GRB 241001A: BOOTES-6/DPRT optical upper limit
  93. LIGO/Virgo/KAGRA S241002e: Identification of a GW compact binary merger candidate
  94. GRB 241002A: Swift detection of a burst
  95. LIGO/Virgo/KAGRA S240930du: Updated Sky localization
  96. GRB 240930B: Fermi GBM Observation
  97. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  98. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  99. EP240930a: EP-WXT detection of a fast X-ray transient
  100. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607

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