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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"

5161 results found.

  1. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  2. Fermi trigger No 736967879: Global MASTER-Net observations report
  3. Fermi trigger No 736564880: Global MASTER-Net observations report
  4. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  5. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  6. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  7. GRB 240503A: AstroSat CZTI detection
  8. Fermi GRB 240501A: Global MASTER-Net observations report
  9. Fermi trigger No 736197684: Global MASTER-Net observations report
  10. GRB 240426A: VZLUSAT-2 detection
  11. GRB 240407A: VZLUSAT-2 detection
  12. Fermi-LAT gamma-ray observations of IceCube-240424A
  13. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  14. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  15. GRB 240426A: AstroSat CZTI detection
  16. LIGO/Virgo/KAGRA S240422ed: BOOTES-4/MET Optical Upper Limits for EP240426a
  17. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  18. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  19. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  20. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  21. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  22. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  23. S240422ed: MeerLICHT/BlackGEM photometry on AT2024hfx and archival ZTF detection
  24. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  25. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  26. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  27. LIGO/Virgo/KAGRA S240422ed: Additional DECam GW-MMADS Candidates from the first two nights of observations
  28. Fermi trigger No 735697285: Global MASTER-Net observations report
  29. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  30. LIGO/Virgo/KAGRA S240422ed: Vetting of DECam Candidates Using Real-Time Resources and SAGUARO Infrastructure
  31. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  32. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  33. LIGO/Virgo/KAGRA S240422ed: MOSFIRE spectroscopy of the DECam GW-MMADS candidate AT 2024hdn
  34. LIGO/Virgo/KAGRA S240422ed: ATCA follow-up of candidate counterparts
  35. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  36. LIGO/Virgo/KAGRA S240422ed: Early X-ray Upper Limits from EP-WXT for the LVK Sky Localization Region
  37. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of Mag24a
  38. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  39. LIGO/Virgo/KAGRA S240422ed: DECam GW-MMADS Candidates
  40. IceCube Alert 240424.08: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S240422ed: SAGUARO upper limits from CSS
  42. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  43. LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from ATLAS observations
  44. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  45. Fermi trigger No 735470374: Global MASTER-Net observations report
  46. Fermi GRB 240422A: Global MASTER-Net observations report
  47. GRB 240422A: Fermi GBM Final Real-time Localization
  48. GRB 240421B: Swift-XRT refined Analysis
  49. EP240420a: Xinglong decaying optical counterpart
  50. Fermi trigger No 735280430: Global MASTER-Net observations report
  51. IceCube Alert 240419.98: Global MASTER-Net observations report
  52. GRB 240419B: Swift-XRT refined Analysis
  53. Swift GRB 240419A: Global MASTER-Net observations report
  54. GRB 240419A: Swift-XRT refined Analysis
  55. GRB 240418A: Swift-XRT refined Analysis
  56. GRB 240418A: Swift detection of a burst
  57. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  58. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  59. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  60. EP 240414a: BOOTES-4/MET Optical Upper Limits
  61. Fermi GRB 240415A: Global MASTER-Net observations report
  62. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  63. Swift Trigger 1220736: detection of 4U 1543-62.
  64. Fermi GRB 240407A: Global MASTER-Net observations report
  65. LXT 240402A: MASTER optical observations with AGN in error-box
  66. Fermi GRB 240402A: Global MASTER-Net observations report
  67. X-ray transient EP20240331a: MeerLICHT optical upper limits
  68. GRB 240324A: AstroSat CZTI detection of a short burst
  69. Fermi GRB 240328B: Global MASTER-Net observations report
  70. Fermi GRB 240328A: Global MASTER-Net observations report
  71. X-ray transient EP240315a: continued ATCA monitoring
  72. Fermi trigger No 733092476: Global MASTER-Net observations report
  73. Fermi trigger No 732937833: Global MASTER-Net observations report
  74. Fermi GRB 240320A: Global MASTER-Net observations report
  75. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  76. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  77. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  78. Fermi GRB 240317B: Global MASTER-Net observations report
  79. Fermi GRB 240317A: Global MASTER-Net observations report
  80. GRB 240317B: Fermi GBM Final Real-time Localization
  81. Fermi trigger No 732299243: Global MASTER-Net observations report
  82. GRB 240309A: MAXI/GSC detection
  83. GRB 231215A: further radio observations with the VLA
  84. Fermi GRB 240306A: Global MASTER-Net observations report
  85. Fermi GRB 240305A: Global MASTER-Net observations report
  86. Improved IPN triangulation of GRB 240227A (short)
  87. Fermi trigger No 731161136: Global MASTER-Net observations report
  88. Fermi GRB 240229A: Global MASTER-Net observations report
  89. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  90. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  91. Transient EPW20240219aa: J-band upper limits from WINTER
  92. GRB 240225B: GOTO detection of a candidate optical afterglow
  93. GRB 240222A: ATCA radio observations
  94. VLA X-band observation of EPW20240219aa
  95. GRB 240222A: Swift-XRT refined Analysis
  96. Fermi trigger No 729914426: Global MASTER-Net observations report
  97. GRB 240215A: Swift/BAT-GUANO localization of a burst
  98. Fermi trigger No 729703985: Global MASTER-Net observations report
  99. GRB 240214A/1H 0451-560: MAXI/GSC detection
  100. Fermi trigger No 729152364: Global MASTER-Net observations report

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