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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21983 results found.

  1. GRB 240513A: Swift-XRT observations
  2. Fermi GRB 240514B: Global MASTER-Net observations report
  3. transient: Xinglong Nearby Galaxy Supernova Survey detection of AT2024iss
  4. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  5. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  6. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  7. GRB 240513A: Tiled Swift observations
  8. LAT GRB240513.31: Global MASTER-Net observations report
  9. Fermi GRB 240513B: Global MASTER-Net observations report
  10. Fermi trigger No 737277727: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  12. Fermi trigger No 737258655: Global MASTER-Net observations report
  13. GRB 240511A: J-band observations with WINTER
  14. Fermi trigger No 737247400: Global MASTER-Net observations report
  15. Fermi trigger No 737244199: Global MASTER-Net observations report
  16. Fermi trigger No 737218721: Global MASTER-Net observations report
  17. Fermi trigger No 737196587: Global MASTER-Net observations report
  18. Fermi trigger No 737168073: Global MASTER-Net observations report
  19. GRB 240511A: optical afterglow detection from the NOT
  20. Fermi trigger No 737173236: Global MASTER-Net observations report
  21. Fermi GRB 240511A: Global MASTER-Net observations report
  22. Swift GRB 240511A: Global MASTER-Net observations report
  23. Fermi trigger No 737105243: Global MASTER-Net observations report
  24. Fermi trigger No 737152719: Global MASTER-Net observations report
  25. Fermi trigger No 737102480: Global MASTER-Net observations report
  26. Fermi trigger No 737111207: Global MASTER-Net observations report
  27. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  28. LIGO/Virgo/KAGRA S240422ed: P200 observations of AT2024hit
  29. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  30. Fermi trigger No 736967879: Global MASTER-Net observations report
  31. EP240506a: CrAO ZTSH optical upper limit
  32. EP240506a: Archival radio searching
  33. EP240506a: TRT optical upper limit
  34. Fermi trigger No 736733320: Global MASTER-Net observations report
  35. EP240506a: Optical upper limit with Kinder observations
  36. EP240506a: EP-WXT detection of a new fast X-ray transient
  37. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  38. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  39. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  40. Fermi trigger No 736564880: Global MASTER-Net observations report
  41. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  42. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  43. Fermi trigger No 736461232: Global MASTER-Net observations report
  44. Fermi GRB 240504A: Global MASTER-Net observations report
  45. Fermi trigger No 736472503: Global MASTER-Net observations report
  46. GW170817: VLA observations at ~5.5 yrs since merger
  47. Fermi trigger No 736387941: Global MASTER-Net observations report
  48. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  49. GRB 240502A: GOTO optical upper limit
  50. Fermi trigger No 736379109: Global MASTER-Net observations report
  51. GRB 240502C: GOTO possible optical counterpart candidates
  52. Fermi GRB 240502B: Global MASTER-Net observations report
  53. Fermi GRB 240502A: Global MASTER-Net observations report
  54. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  55. Integral GRB240502.23: Global MASTER-Net observations report
  56. LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP
  57. Fermi GRB 240501A: Global MASTER-Net observations report
  58. Fermi trigger No 736197684: Global MASTER-Net observations report
  59. MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
  60. X-ray transient EP240414a: Detection of associated supernova
  61. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  62. Additional DECam GW-MMADS Candidates from three nights of observations
  63. Fermi-LAT gamma-ray observations of IceCube-240424A
  64. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
  65. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
  66. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  67. Fermi GRB 240428A: Global MASTER-Net observations report
  68. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
  69. LIGO/Virgo/KAGRA S240422ed: Observations with 1.6m Mephisto
  70. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  71. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  72. EP240426b: EP-WXT detection of a new fast X-ray transient
  73. LIGO/Virgo/KAGRA S240422ed: Archival radio detection of EP240426a
  74. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfq, AT2024hfr, AT2024hfs, and AT2024hfx
  75. LIGO/Virgo/KAGRA S240422ed: BOOTES-6/DPRT optical upper limits for EP240426a
  76. LIGO/Virgo/KAGRA S240422ed: GRANDMA Optical Upper Limits for EP240426a
  77. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  78. GRB 240414A: NOEMA detection
  79. LIGO/Virgo/KAGRA S240422ed: EP240426a possible optical detection
  80. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  81. LVK S240422ed: Further Swift-XRT followup of three sources
  82. LIGO/Virgo/KAGRA S240422ed: EP-FXT detection of a candidate counterpart EP240426a
  83. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  84. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis
  85. LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search update and AT2024hfx, AT2024hgl observations
  86. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  87. LIGO/Virgo/KAGRA S240422ed: PRIME near-infrared observations
  88. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  89. S240422ed: MeerLICHT/BlackGEM photometry on AT2024hfx and archival ZTF detection
  90. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  91. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  92. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  93. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  94. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA and Kilonova-Catcher galaxy targeting observations
  95. LIGO/Virgo/KAGRA S240422ed: Additional DECam GW-MMADS Candidates from the first two nights of observations
  96. LIGO/Virgo/KAGRA S240422ed: ANU 2.3m followup of candidate counterparts
  97. LIGO/Virgo/KAGRA S240422ed: Magellan Spectrum of GW-MMADS Candidate AT2024hdo Indicates a Type II SN
  98. Fermi trigger No 735697285: Global MASTER-Net observations report
  99. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
  100. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101

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