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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"

21097 results found.

  1. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  2. transient SPT-SVJ025406.5-702837: ATCA follow-up observations
  3. Fermi GRB 230807A: Global MASTER-Net observations report
  4. Fermi trigger No 713134237: Global MASTER-Net observations report
  5. GRB 230805B : OHP/T193 optical upper limit
  6. GRB 230805B: Swift/UVOT Upper Limits
  7. Fermi trigger No 712991593: Global MASTER-Net observations report
  8. GRB 230805B: Bassano Bresciano observatory upper limit
  9. Fermi trigger No 712987357: Global MASTER-Net observations report
  10. GRB 230805B: NOT optical afterglow confirmation
  11. Fermi GRB 230805A: Global MASTER-Net observations report
  12. GRB 230805B: SAO RAS optical observations
  13. Fermi trigger No 712927418: Global MASTER-Net observations report
  14. Swift GRB 230805B: Global MASTER-Net observations report
  15. Fermi trigger No 712798043: Global MASTER-Net observations report
  16. GRB 230802A: Swift/UVOT Upper Limits
  17. Fermi trigger No 712718833: Global MASTER-Net observations report
  18. Fermi trigger No 712713532: Global MASTER-Net observations report
  19. Fermi trigger No 712651827: Global MASTER-Net observations report
  20. Swift GRB 230802A: Global MASTER-Net observations report
  21. LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
  22. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  23. IceCube-230724A: JCMT/SCUBA-2 submm observations
  24. IceCube-230707A: JCMT/SCUBA-2 submm observations
  25. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  26. GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
  27. Fermi trigger No 712390645: Global MASTER-Net observations report
  28. Fermi-LAT gamma-ray observations of IceCube-230727A
  29. Fermi trigger No 712306969: Global MASTER-Net observations report
  30. IceCube-230727A: No candidates from the Zwicky Transient Facility
  31. GRB 230728A: Swift/UVOT Upper Limits
  32. GRB 230728A: NOT optical observations and possible host galaxy
  33. IceCube-230724A: No counterparts from the Zwicky Transient Facility
  34. Swift GRB230728.12: Global MASTER-Net observations report
  35. Fermi-LAT gamma-ray observations of IceCube-230725A
  36. Fermi-LAT gamma-ray observations of IceCube-230724A
  37. Fermi trigger No 712143685: Global MASTER-Net observations report
  38. Integral GRB230726.26: Global MASTER-Net observations report
  39. GRB 230723B: Further CAHA observations and host galaxy detection
  40. GRB 230723B: ATCA rapid radio follow-up
  41. Integral GRB230725.99: Global MASTER-Net observations report
  42. IceCube Alert 230725.90: Global MASTER-Net observations report
  43. GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
  44. GRB 230723B: Leavitt Observatory upper limit
  45. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  46. GRB 230723B: Montarrenti Observatory upper limit
  47. GRB 230723B: Optical afterglow candidate from CAHA
  48. GRB 230723B: Bassano Bresciano Observatory upper limit
  49. GRB 230723B: non-detections from Observatoire de Haute-Provence
  50. IceCube Alert 230724.08: Global MASTER-Net observations report
  51. Fermi trigger No 711853834: Global MASTER-Net observations report
  52. Fermi trigger No 711805358: Global MASTER-Net observations report
  53. GRB 230723B: Swift/UVOT Upper Limits
  54. Swift GRB 230723B: Global MASTER-Net observations report
  55. GRB 230723B: Swift-XRT observations
  56. Fermi GRB 230723A: Global MASTER-Net observations report
  57. Swift GRB230720.30: Global MASTER-Net observations report
  58. Fermi trigger No 711088412: Global MASTER-Net observations report
  59. Fermi GRB 230713A: Global MASTER-Net observations report
  60. Fermi trigger No 710741042: Global MASTER-Net observations report
  61. IceCube-230707A: No candidates detected by Swift-XRT
  62. IceCube-230707A: No candidates from the Zwicky Transient Facility
  63. Fermi-LAT gamma-ray observations of IceCube-230708A
  64. Fermi-LAT gamma-ray observations of IceCube-230707B
  65. Fermi-LAT gamma-ray observations of IceCube-230707A
  66. GRB 230707A: Swift-XRT observations
  67. IceCube Alert 230708.35: Global MASTER-Net observations report
  68. IceCube Alert 230707.71: Global MASTER-Net observations report
  69. GRB 230707A: Swift ToO observations
  70. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
  71. ZTF23aaoohpy/AT2023lcr : HCT follow-up observations
  72. Fermi GRB 230707A: Global MASTER-Net observations report
  73. Integral GRB230706.70: Global MASTER-Net observations report
  74. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  75. ZTF23aaoohpy/AT2023lcr: AMI-LA radio detection
  76. Fermi trigger No 710117592: Global MASTER-Net observations report
  77. GRB 230328B: LBT detection of the likely host galaxy
  78. LIGO/Virgo/KAGRA S230627c: observations of ZTF23aaptsuy/AT2023lx in AbAO observatory
  79. GRB 230628E: Swift/UVOT Detection
  80. GRB 230628E: ATCA rapid radio follow-up
  81. LIGO/Virgo/KAGRA S230627c: GRANDMA observations of galaxies and ZTF counterpart candidates
  82. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  83. GRB 230628E - VLT spectroscopic observations
  84. ZTF23aaoohpy/AT2023lcr: LBT observations
  85. Fermi GRB 230628C: Global MASTER-Net observations report
  86. GRB230628E: VLT optical identification of afterglow candidate
  87. Fermi GRB 230628D: Global MASTER-Net observations report
  88. Swift GRB230628.93: Global MASTER-Net observations report
  89. LIGO/Virgo/KAGRA S230516az: GOTO candidate counterpart GOTO23hu ruled out by Zwicky Transient Facility observations
  90. LIGO/Virgo/KAGRA S230627c: Additional observations from the Zwicky Transient Facility
  91. AT2023lcr: JCMT SCUBA-2 sub-mm observations
  92. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  93. LIGO/Virgo/KAGRA S230627c: Global MASTER-Net observations report
  94. LIGO/Virgo/Kagra S230627c: NED Galaxies in the Localization Volume
  95. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  96. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  97. GRB 230623A: Swift-XRT observations
  98. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  99. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  100. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations

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