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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"

32720 results found.

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

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