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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"

32725 results found.

  1. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  2. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  3. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  4. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  5. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  6. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  7. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  8. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  9. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  10. GRB 241120A: GRBAlpha detection
  11. GRB 241113B: SVOM/VT optical afterglow observations
  12. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  13. Konus-Wind detection of GRB 241117A
  14. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  15. GRB 241105A: ATCA radio detection
  16. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  17. IPN triangulation of GRB 241117A
  18. GRB 241026A: VIRT Optical Upper Limit
  19. GRB 241025A: VIRT Optical Upper Limit
  20. Konus-Wind detection of GRB 241120A
  21. GRB241120A: OHP/T193 optical observations
  22. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  23. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  24. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  25. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  26. GRB 241120A: Mondy and AbAO optical observations
  27. EP241119a: Optical upper limits with Kinder observations
  28. EP241119a: GIT optical upper limits
  29. GRB 241113A: Possible ATCA Radio detection
  30. EP241119a : J-band observations with WINTER
  31. GRB 241120A: Fermi GBM Observation
  32. EP241119a: Global MASTER-Net observations report
  33. GRB241120A: a long GRB detected by INTEGRAL
  34. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  35. GRB 241112B: Mephisto further optical observations
  36. GRB 241030A: J-band observations
  37. GRB 241115a: PRIME near-infrared upper limits
  38. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  39. GRB 241115B: Fermi GBM Observation
  40. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  41. Fermi GRB 241118A: Global MASTER-Net observations report
  42. Updates to IceCube realtime alert system for muon tracks
  43. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  44. Fermi GRB 241117B: Global MASTER-Net observations report
  45. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  46. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  47. Fermi GRB 241117A: Global MASTER-Net observations report
  48. GRB 241115C: Fermi GBM Observation
  49. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  50. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  51. GRB 241115A: Mephisto upper limits
  52. GRB 241113B: Mephisto upper limits
  53. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  54. GRB 241115D / EP 241115a: SVOM/GRM observation
  55. The EP-WXT trigger 01709120856 is likely a flaring star
  56. EP241113a: Swift XRT weak detection
  57. GRB 241115A: Fermi GBM Observation
  58. GRB 241115A: LCOGT Optical Upper Limits
  59. Fermi GRB 241115B: Global MASTER-Net observations report
  60. LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
  61. EP241115a: Global MASTER-Net observations report
  62. LIGO/Virgo/KAGRA S241113p: Updated Sky localization
  63. EP241113a: No Detection in Fermi-GBM Observations
  64. Swift GRB 241115A: Global MASTER-Net observations report
  65. Fermi GRB 241115A: Global MASTER-Net observations report
  66. EP 241113a: LBT possible optical counterpart
  67. GRB 241113B: KAIT Optical Afterglow Candidate
  68. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  69. GRB 241113A: Swift-BAT refined analysis
  70. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  71. GRB 241113A: PRIME near-infrared upper limits
  72. Fermi GRB 241114A: Global MASTER-Net observations report
  73. EP241113a: Global MASTER-Net observations report
  74. GRB 241113B: J-band upper limit from WINTER
  75. GRB 241113A: J-band observations with WINTER
  76. EP241113a : J-band observations with WINTER
  77. GRB 241030A: LCO optical observation
  78. IceCube-241113A: Upper limits from a search for additional neutrino events in IceCube
  79. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  80. GRB 241113A: KAIT optical observations
  81. EP241113b: Global MASTER-Net observations report
  82. EP241113b/GRB 241113B: EP detection of GRB 241113B
  83. Fermi-LAT gamma-ray observations of IceCube-241113A
  84. GRB 241113B: SVOM/GRM observation
  85. LIGO/Virgo/KAGRA S241114y: Identification of a GW compact binary merger candidate
  86. EP241107a: SOAR upper limits
  87. GRB 241113A: Swift/UVOT Detection
  88. GRB 241113A: REM detection of the optical/NIR afterglow
  89. Konus-Wind detection of GRB 241107A (short/hard)
  90. LIGO/Virgo/KAGRA S241113p: Identification of a GW compact binary merger candidate
  91. GRB 241113B: Swift ToO observations
  92. GRB 241113A: LCO optical observations
  93. GRB 241112B: GMG Optical Upper Limit
  94. GRB241113A: LCOGT (40-cm) optical counterpart detection
  95. GRB 241113A: MASTER010615.66-224018.2 optical counterpart detection
  96. SVOM/GRM detection of a short burst from SGR 1E1841-045
  97. LIGO/Virgo/KAGRA S241111bn: Updated Sky localization
  98. GRB 241105A: ATCA Radio Upper Limits
  99. GRB 241112B: AbAO optical upper limit
  100. GRB 241107A: GROWTH-India telescope optical upper limit

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