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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"

21106 results found.

  1. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  2. LIGO/Virgo/KAGRA S230627c: Global MASTER-Net observations report
  3. LIGO/Virgo/Kagra S230627c: NED Galaxies in the Localization Volume
  4. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  5. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  6. GRB 230623A: Swift-XRT observations
  7. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  8. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  9. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  10. GRB 230623A: Tiled Swift observations
  11. MAXI GRB 230623A: MASTER optical observations
  12. GRB 230623A: Tiled Swift observations
  13. GRB 230622A: ATCA rapid radio follow-up
  14. Swift GRB 230622A: Global MASTER-Net observations report
  15. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic classification of GOTO23hn
  16. LIGO/Virgo S230622e: Global MASTER-Net observations report
  17. LIGO/Virgo S230621bq: Global MASTER-Net observations report
  18. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  19. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic redshift of the host galaxy of GOTO23hn
  20. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  21. Fermi trigger No 709083929: Global MASTER-Net observations report
  22. AT2023lcr: VLA radio detection
  23. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  24. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  25. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  26. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  27. LIGO/Virgo S230620au: Global MASTER-Net observations report
  28. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  29. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  30. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  31. AT2023lcr: Pan-STARRS & ATLAS Observations
  32. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  33. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  34. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  35. LIGO/Virgo S230620al: Global MASTER-Net observations report
  36. LIGO/Virgo S230620af: Global MASTER-Net observations report
  37. LIGO/Virgo S230620z: Global MASTER-Net observations report
  38. LIGO/Virgo S230620w: Global MASTER-Net observations report
  39. LIGO/Virgo S230619bg: Global MASTER-Net observations report
  40. LIGO/Virgo S230620g: Global MASTER-Net observations report
  41. LIGO/Virgo S230619ay: Global MASTER-Net observations report
  42. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  43. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  44. LIGO/Virgo S230619bd: Global MASTER-Net observations report
  45. LIGO/Virgo S230619bb: Global MASTER-Net observations report
  46. LIGO/Virgo S230619as: Global MASTER-Net observations report
  47. LIGO/Virgo S230619ap: Global MASTER-Net observations report
  48. ZTF23aaoohpy/AT2023lcr: GROWTH-India Telescope follow-up observations
  49. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  50. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  51. ZTF23aaoohpy/AT2023lcr: Zwicky Transient Facility discovery of a fast fading red transient
  52. LIGO/Virgo S230619i: Global MASTER-Net observations report
  53. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates
  54. LIGO/Virgo S230619aa: Global MASTER-Net observations report
  55. LIGO/Virgo S230619x: Global MASTER-Net observations report
  56. LIGO/Virgo S230619e: Global MASTER-Net observations report
  57. LIGO/Virgo S230618at: Global MASTER-Net observations report
  58. LIGO/Virgo S230618ba: Global MASTER-Net observations report
  59. LIGO/Virgo S230618az: Global MASTER-Net observations report
  60. LIGO/Virgo S230618ae: Global MASTER-Net observations report
  61. LIGO/Virgo S230618aq: Global MASTER-Net observations report
  62. LIGO/Virgo S230618y: Global MASTER-Net observations report
  63. LIGO/Virgo S230618s: Global MASTER-Net observations report
  64. GRB 230618A: Swift/UVOT Upper Limits
  65. GRB 230616A: Swift-XRT observations
  66. LIGO/Virgo S230618r: Global MASTER-Net observations report
  67. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  68. LIGO/Virgo S230615an: Global MASTER-Net observations report
  69. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  70. GRB 230618A: KAIT Optical Observations
  71. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  72. LIGO/Virgo S230618k: Global MASTER-Net observations report
  73. LIGO/Virgo S230618d: Global MASTER-Net observations report
  74. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  75. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  76. LIGO/Virgo S230617ab: Global MASTER-Net observations report
  77. Swift GRB 230618A: Global MASTER-Net observations report
  78. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  79. GRB230618A: LCOGT Optical Observations
  80. GRB 230616A: Swift ToO observations
  81. LIGO/Virgo/KAGRA S230615az: T80S Search and Candidate Counterpart Identification
  82. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  83. LIGO/Virgo/KAGRA S230615az: Xinglong-2.16m photometric observations of GIT candidates
  84. LIGO/Virgo/KAGRA S230615az: GOTO candidate counterparts
  85. LIGO/Virgo S230616s: Global MASTER-Net observations report
  86. LIGO/Virgo S230615be: Global MASTER-Net observations report
  87. LIGO/Virgo S230615af: Global MASTER-Net observations report
  88. LIGO/Virgo S230616j: Global MASTER-Net observations report
  89. LIGO/Virgo S230615av: Global MASTER-Net observations report
  90. LIGO/Virgo S230615az: Global MASTER-Net observations report
  91. LIGO/Virgo S230615ax: Global MASTER-Net observations report
  92. LIGO/Virgo S230615k: Global MASTER-Net observations report
  93. LIGO/Virgo S230615t: Global MASTER-Net observations report
  94. LIGO/Virgo S230615i: Global MASTER-Net observations report
  95. LIGO/Virgo S230613at: Global MASTER-Net observations report
  96. LIGO/Virgo S230614ac: Global MASTER-Net observations report
  97. LIGO/Virgo S230614t: Global MASTER-Net observations report
  98. LIGO/Virgo S230614o: Global MASTER-Net observations report
  99. Fermi trigger No 708426906: Global MASTER-Net observations report
  100. GRB 230606A: LCOGT Optical Observations

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