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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

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To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').

95 results found.

  1. GW s240422ed: Swift UVOT follow-up
  2. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  3. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  4. LIGO/Virgo/KAGRA S240422ed: Las Cumbres Observatory Follow-up Observations of the Localization Region
  5. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  6. LIGO/Virgo/KAGRA S240422ed: P200 observations of AT2024hit
  7. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  8. LIGO/Virgo/KAGRA S240422ed: Upper limits from a two-week IceCube neutrino search
  9. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  10. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  11. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  12. LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP
  13. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  14. Additional DECam GW-MMADS Candidates from three nights of observations
  15. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
  16. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
  17. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  18. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
  19. LIGO/Virgo/KAGRA S240422ed: DDOTI Optical Upper Limit for J-GEM24a
  20. LIGO/Virgo/KAGRA S240422ed: Observations with 1.6m Mephisto
  21. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  22. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  23. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  24. EP240426b: EP-WXT detection of a new fast X-ray transient
  25. LIGO/Virgo/KAGRA S240422ed: Archival radio detection of EP240426a
  26. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfq, AT2024hfr, AT2024hfs, and AT2024hfx
  27. LIGO/Virgo/KAGRA S240422ed: BOOTES-6/DPRT optical upper limits for EP240426a
  28. LIGO/Virgo/KAGRA S240422ed: GRANDMA Optical Upper Limits for EP240426a
  29. LIGO/VIRGO/KAGRA S240422ed: Historical variability for EP240426a
  30. XMM-Newton observation of EP240426a
  31. LIGO/Virgo/KAGRA S240422ed: BOOTES-4/MET Optical Upper Limits for EP240426a
  32. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  33. LIGO/Virgo/KAGRA S240422ed: EP240426a possible optical detection
  34. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  35. LVK S240422ed: Further Swift-XRT followup of three sources
  36. LIGO/Virgo/KAGRA S240422ed: EP-FXT detection of a candidate counterpart EP240426a
  37. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  38. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis
  39. LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search update and AT2024hfx, AT2024hgl observations
  40. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  41. LIGO/Virgo/KAGRA S240422ed: PRIME near-infrared observations
  42. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  43. S240422ed: MeerLICHT/BlackGEM photometry on AT2024hfx and archival ZTF detection
  44. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  45. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  46. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  47. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  48. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA and Kilonova-Catcher galaxy targeting observations
  49. LIGO/Virgo/KAGRA S240422ed: Additional DECam GW-MMADS Candidates from the first two nights of observations
  50. LIGO/Virgo/KAGRA S240422ed: ANU 2.3m followup of candidate counterparts
  51. LIGO/Virgo/KAGRA S240422ed: Magellan Spectrum of GW-MMADS Candidate AT2024hdo Indicates a Type II SN
  52. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
  53. LIGO/Virgo/KAGRA S240422ed: Archival BlackGEM/MeerLICHT detections of AT 2024hdr & AT 2024hdq
  54. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  55. LIGO/Virgo/KAGRA S240422ed: No significant counterpart candidates in HAWC observations
  56. LIGO/Virgo/KAGRA S240422ed: Vetting of DECam Candidates Using Real-Time Resources and SAGUARO Infrastructure
  57. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  58. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  59. LIGO/Virgo/KAGRA S240422ed: MOSFIRE spectroscopy of the DECam GW-MMADS candidate AT 2024hdn
  60. LIGO/Virgo/KAGRA S240422ed: ATCA follow-up of candidate counterparts
  61. LIGO/Virgo/KAGRA S240422ed: MOSFIRE imaging of the DECam GW-MMADS candidate AT 2024hdm
  62. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  63. LIGO/Virgo/KAGRA S240422ed: Early X-ray Upper Limits from EP-WXT for the LVK Sky Localization Region
  64. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of Mag24a
  65. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  66. LIGO/Virgo/KAGRA S240422ed: Archival DECaPSs2 observations of the field of Mag24a
  67. LIGO/Virgo/KAGRA S240422ed: DECam GW-MMADS Candidates
  68. LIGO/Virgo/KAGRA S240422ed: Potential Magellan candidates from GCN 36263 are unrelated.
  69. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  70. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
  71. LIGO/Virgo/KAGRA S240422ed: Magellan Detection of a Potential Electromagnetic Counterpart
  72. LIGO/Virgo/KAGRA S240422ed: SAGUARO upper limits from CSS
  73. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  74. LIGO/Virgo/KAGRA S240422ed: LAST optical observations
  75. LIGO/Virgo/KAGRA S240422ed: Potential Candidates from Magellan galaxy-based search
  76. LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
  77. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  78. LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from Pan-STARRS observations of the skymap
  79. LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search
  80. LIGO/Virgo/KAGRA S240422ed: No Counterparts in DDOTI/OAN Optical Observations
  81. LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from ATLAS observations
  82. LIGO/Virgo/KAGRA S240422ed: WINTER near-infrared J-band observations
  83. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  84. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility observations and candidates
  85. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam observations
  86. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  87. LIGO/Virgo/KAGRA S240422ed: Updated NED Galaxies in the Localization Volume
  88. LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
  89. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  90. LIGO/Virgo/KAGRA S240422ed: Updated Sky localization and EM Bright Classification
  91. LIGO/Virgo/KAGRA S240422ed: Coverage and upper limits from MAXI/GSC observations
  92. LIGO/Virgo/KAGRA S240422ed: MeerLICHT and BlackGEM observations report
  93. LIGO/Virgo/KAGRA S240422ed: Identification of a GW compact binary merger candidate
  94. LIGO/Virgo/Kagra S240422ed: NED Galaxies in the Localization Volume
  95. LIGO/Virgo/KAGRA S240422ed: Global MASTER-Net observations report

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